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PCI/CMA: Fixup init race #2

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Merged
merged 1 commit into from
Sep 4, 2023
Merged

PCI/CMA: Fixup init race #2

merged 1 commit into from
Sep 4, 2023

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twilfredo
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@twilfredo twilfredo commented Sep 4, 2023

When device_initcall() is used to invoke pci_cma_keyring_init(), there exists a race between pci_cma_keyring_init() and pci_cma_init(). Running through QEMU, pci_cma_init() is always called first and thus eventually leads to a NULL ptr de-reference as spdm_create() is called before pci_cma_keyring is initialized (setting keyring to NULL in the spdm state).

Change device_initcall to subsys_initcall, to make sure pci_cma_keyring_init is prioritized.

Notes:
Is it safe to use subsys_init() here? Alternatively, couldn't pci_cma_keyring_init() just be called within pci_cma_keyring_init()?

It appears when `device_initcall()` is used to invoke
`pci_cma_keyring_init()`, there exists a race between
pci_cma_keyring_init() and pci_cma_init(). Running through QEMU
pci_cma_init() is always called first and thus eventually leads to a
NULL ptr dereference as spdm_create() is called before pci_cma_keyring
is initialized.

This fix ammends that.

Signed-off-by: Wilfred Mallawa <[email protected]>
@l1k l1k force-pushed the doe branch 3 times, most recently from 0566a0d to b52d0c7 Compare September 4, 2023 08:49
@l1k
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l1k commented Sep 4, 2023

I think on x86, PCI devices are enumerated at subsys_initcall time (via acpi_init() -> acpi_scan_init() -> acpi_bus_scan() -> acpi_bus_attach() -> acpi_pci_root_add() -> pci_acpi_scan_root() -> acpi_pci_root_create() -> pci_scan_child_bus()) and I think the order within one initcall level isn't guaranteed. (I guess it depends on the link order.)

So the keyring needs to be allocated one initcall level earlier than subsys_initcall, which is arch_initcall. I've amended my branch accordingly.

About calling pci_cma_keyring_init() from pci_cma_init(): If there are initially no CMA-capable devices in the system but one is later hotplugged, user space should be able to poke keys into the keyring already before the CMA-capable device is hotplugged. That wouldn't be possible if pci_cma_keyring_init() is called from pci_cma_init().

Good catch that we should bail out of pci_cma_init() if keyring allocation failed. I don't think we need a per-device error message here, the single one emitted earlier on keyring allocation should be sufficient. I've amended the commit "PCI/CMA: Expose in sysfs whether devices are authenticated" to set pdev->cma_init_failed to true in that case.

Likewise good catch about returning an error from the initcall. The error isn't evaluated by the callers of do_one_initcall(), nevertheless returning an error is good code hygiene.

I've spotted another bug in pci_cma_destroy(), it should only call spdm_destroy() if pdev->spdm_state isn't NULL. This code path is only exercised on hot-unplug, which I suppose nobody has ever done so far.

I've added your Signed-off-by to the commit message to acknowledge your contribution. Once again thanks a lot for your testing efforts.

@l1k l1k closed this Sep 4, 2023
@l1k l1k reopened this Sep 4, 2023
@l1k l1k merged commit eee4b2b into l1k:doe Sep 4, 2023
@l1k
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l1k commented Sep 4, 2023

I've reopened and merged this so that you get a violet "Merged" logo in your GitHub dashboard (instead if a red "Closed" logo), then force-pushed my local branch. For upstream I have to fold your changes into the existing commits (instead of separate ones) to make life easier for reviewers.

@twilfredo
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I think on x86, PCI devices are enumerated at subsys_initcall time (via acpi_init() -> acpi_scan_init() -> acpi_bus_scan() -> acpi_bus_attach() -> acpi_pci_root_add() -> pci_acpi_scan_root() -> acpi_pci_root_create() -> pci_scan_child_bus()) and I think the order within one initcall level isn't guaranteed. (I guess it depends on the link order.)

So the keyring needs to be allocated one initcall level earlier than subsys_initcall, which is arch_initcall. I've amended my branch accordingly.

About calling pci_cma_keyring_init() from pci_cma_init(): If there are initially no CMA-capable devices in the system but one is later hotplugged, user space should be able to poke keys into the keyring already before the CMA-capable device is hotplugged. That wouldn't be possible if pci_cma_keyring_init() is called from pci_cma_init().

Good catch that we should bail out of pci_cma_init() if keyring allocation failed. I don't think we need a per-device error message here, the single one emitted earlier on keyring allocation should be sufficient. I've amended the commit "PCI/CMA: Expose in sysfs whether devices are authenticated" to set pdev->cma_init_failed to true in that case.

Likewise good catch about returning an error from the initcall. The error isn't evaluated by the callers of do_one_initcall(), nevertheless returning an error is good code hygiene.

I've spotted another bug in pci_cma_destroy(), it should only call spdm_destroy() if pdev->spdm_state isn't NULL. This code path is only exercised on hot-unplug, which I suppose nobody has ever done so far.

I've added your Signed-off-by to the commit message to acknowledge your contribution. Once again thanks a lot for your testing efforts.

Thanks for the detailed response! it's cleared a few things up for me.

@twilfredo
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I've reopened and merged this so that you get a violet "Merged" logo in your GitHub dashboard (instead if a red "Closed" logo), then force-pushed my local branch. For upstream I have to fold your changes into the existing commits (instead of separate ones) to make life easier for reviewers.

Yep all good! cheers for that!

l1k pushed a commit that referenced this pull request Sep 5, 2023
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.

Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.

They _must_ be nested correctly to avoid deadlock:

  lock(stab->lock)
    : do BPF map operations and psock insert/delete
    lock(psock->link_lock)
       : add map to psock linked list of maps
    unlock(psock->link_lock)
  unlock(stab->lock)

For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:

   rcu_critical_section:
      raw_spin_lock(stab->lock)
         spin_lock(psock->link_lock) <- may sleep ouch
         spin_unlock(psock->link_lock)
      raw_spin_unlock(stab->lock)
   rcu_critical_section

Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:

./test_progs -t sockmap_basic
[   33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[   33.441933]
[   33.442089] =============================
[   33.442421] [ BUG: Invalid wait context ]
[   33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G           O
[   33.443320] -----------------------------
[   33.443624] test_progs/2073 is trying to lock:
[   33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[   33.444636] other info that might help us debug this:
[   33.444991] context-{5:5}
[   33.445183] 3 locks held by test_progs/2073:
[   33.445498]  #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[   33.446159]  #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[   33.446809]  #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[   33.447445] stack backtrace:
[   33.447655] CPU: 10 PID

To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.

Signed-off-by: John Fastabend <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
l1k pushed a commit that referenced this pull request Sep 5, 2023
…es_lock

__dma_entry_alloc_check_leak() calls into printk -> serial console
output (qcom geni) and grabs port->lock under free_entries_lock
spin lock, which is a reverse locking dependency chain as qcom_geni
IRQ handler can call into dma-debug code and grab free_entries_lock
under port->lock.

Move __dma_entry_alloc_check_leak() call out of free_entries_lock
scope so that we don't acquire serial console's port->lock under it.

Trimmed-down lockdep splat:

 The existing dependency chain (in reverse order) is:

               -> #2 (free_entries_lock){-.-.}-{2:2}:
        _raw_spin_lock_irqsave+0x60/0x80
        dma_entry_alloc+0x38/0x110
        debug_dma_map_page+0x60/0xf8
        dma_map_page_attrs+0x1e0/0x230
        dma_map_single_attrs.constprop.0+0x6c/0xc8
        geni_se_rx_dma_prep+0x40/0xcc
        qcom_geni_serial_isr+0x310/0x510
        __handle_irq_event_percpu+0x110/0x244
        handle_irq_event_percpu+0x20/0x54
        handle_irq_event+0x50/0x88
        handle_fasteoi_irq+0xa4/0xcc
        handle_irq_desc+0x28/0x40
        generic_handle_domain_irq+0x24/0x30
        gic_handle_irq+0xc4/0x148
        do_interrupt_handler+0xa4/0xb0
        el1_interrupt+0x34/0x64
        el1h_64_irq_handler+0x18/0x24
        el1h_64_irq+0x64/0x68
        arch_local_irq_enable+0x4/0x8
        ____do_softirq+0x18/0x24
        ...

               -> #1 (&port_lock_key){-.-.}-{2:2}:
        _raw_spin_lock_irqsave+0x60/0x80
        qcom_geni_serial_console_write+0x184/0x1dc
        console_flush_all+0x344/0x454
        console_unlock+0x94/0xf0
        vprintk_emit+0x238/0x24c
        vprintk_default+0x3c/0x48
        vprintk+0xb4/0xbc
        _printk+0x68/0x90
        register_console+0x230/0x38c
        uart_add_one_port+0x338/0x494
        qcom_geni_serial_probe+0x390/0x424
        platform_probe+0x70/0xc0
        really_probe+0x148/0x280
        __driver_probe_device+0xfc/0x114
        driver_probe_device+0x44/0x100
        __device_attach_driver+0x64/0xdc
        bus_for_each_drv+0xb0/0xd8
        __device_attach+0xe4/0x140
        device_initial_probe+0x1c/0x28
        bus_probe_device+0x44/0xb0
        device_add+0x538/0x668
        of_device_add+0x44/0x50
        of_platform_device_create_pdata+0x94/0xc8
        of_platform_bus_create+0x270/0x304
        of_platform_populate+0xac/0xc4
        devm_of_platform_populate+0x60/0xac
        geni_se_probe+0x154/0x160
        platform_probe+0x70/0xc0
        ...

               -> #0 (console_owner){-...}-{0:0}:
        __lock_acquire+0xdf8/0x109c
        lock_acquire+0x234/0x284
        console_flush_all+0x330/0x454
        console_unlock+0x94/0xf0
        vprintk_emit+0x238/0x24c
        vprintk_default+0x3c/0x48
        vprintk+0xb4/0xbc
        _printk+0x68/0x90
        dma_entry_alloc+0xb4/0x110
        debug_dma_map_sg+0xdc/0x2f8
        __dma_map_sg_attrs+0xac/0xe4
        dma_map_sgtable+0x30/0x4c
        get_pages+0x1d4/0x1e4 [msm]
        msm_gem_pin_pages_locked+0x38/0xac [msm]
        msm_gem_pin_vma_locked+0x58/0x88 [msm]
        msm_ioctl_gem_submit+0xde4/0x13ac [msm]
        drm_ioctl_kernel+0xe0/0x15c
        drm_ioctl+0x2e8/0x3f4
        vfs_ioctl+0x30/0x50
        ...

 Chain exists of:
   console_owner --> &port_lock_key --> free_entries_lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(free_entries_lock);
                                lock(&port_lock_key);
                                lock(free_entries_lock);
   lock(console_owner);

                *** DEADLOCK ***

 Call trace:
  dump_backtrace+0xb4/0xf0
  show_stack+0x20/0x30
  dump_stack_lvl+0x60/0x84
  dump_stack+0x18/0x24
  print_circular_bug+0x1cc/0x234
  check_noncircular+0x78/0xac
  __lock_acquire+0xdf8/0x109c
  lock_acquire+0x234/0x284
  console_flush_all+0x330/0x454
  console_unlock+0x94/0xf0
  vprintk_emit+0x238/0x24c
  vprintk_default+0x3c/0x48
  vprintk+0xb4/0xbc
  _printk+0x68/0x90
  dma_entry_alloc+0xb4/0x110
  debug_dma_map_sg+0xdc/0x2f8
  __dma_map_sg_attrs+0xac/0xe4
  dma_map_sgtable+0x30/0x4c
  get_pages+0x1d4/0x1e4 [msm]
  msm_gem_pin_pages_locked+0x38/0xac [msm]
  msm_gem_pin_vma_locked+0x58/0x88 [msm]
  msm_ioctl_gem_submit+0xde4/0x13ac [msm]
  drm_ioctl_kernel+0xe0/0x15c
  drm_ioctl+0x2e8/0x3f4
  vfs_ioctl+0x30/0x50
  ...

Reported-by: Rob Clark <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Robin Murphy <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
l1k pushed a commit that referenced this pull request Sep 7, 2023
…git/vgupta/arc

Pull ARC updates from Vineet Gupta:

 - fixes for -Wmissing-prototype warnings

 - missing compiler barrier in relaxed atomics

 - some uaccess simplification, declutter

 - removal of massive glocal struct cpuinfo_arc from bootlog code

 - __switch_to consolidation (removal of inline asm variant)

 - use GP to cache task pointer (vs. r25)

 - misc rework of entry code

* tag 'arc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (24 commits)
  ARC: boot log: fix warning
  arc: Explicitly include correct DT includes
  ARC: pt_regs: create seperate type for ecr
  ARCv2: entry: rearrange pt_regs slightly
  ARC: entry: replace 8 byte ADD.ne with 4 byte ADD2.ne
  ARC: entry: replace 8 byte OR with 4 byte BSET
  ARC: entry: Add more common chores to EXCEPTION_PROLOGUE
  ARC: entry: EV_MachineCheck dont re-read ECR
  ARC: entry: ARcompact EV_ProtV to use r10 directly
  ARC: entry: rework (non-functional)
  ARC: __switch_to: move ksp to thread_info from thread_struct
  ARC: __switch_to: asm with dwarf ops (vs. inline asm)
  ARC: kernel stack: INIT_THREAD need not setup @init_stack in @ksp
  ARC: entry: use gp to cache task pointer (vs. r25)
  ARC: boot log: eliminate struct cpuinfo_arc #4: boot log per ISA
  ARC: boot log: eliminate struct cpuinfo_arc #3: don't export
  ARC: boot log: eliminate struct cpuinfo_arc #2: cache
  ARC: boot log: eliminate struct cpuinfo_arc #1: mm
  ARCv2: memset: don't prefetch for len == 0 which happens a alot
  ARC: uaccess: elide unaliged handling if hardware supports
  ...
l1k pushed a commit that referenced this pull request Sep 7, 2023
Currently, for double invoke call_rcu(), will dump rcu_head objects memory
info, if the objects is not allocated from the slab allocator, the
vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock need to
be held, since the call_rcu() can be invoked in interrupt context,
therefore, there is a possibility of spinlock deadlock scenarios.

And in Preempt-RT kernel, the rcutorture test also trigger the following
lockdep warning:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by swapper/0/1:
 #0: ffffffffb534ee80 (fullstop_mutex){+.+.}-{4:4}, at: torture_init_begin+0x24/0xa0
 #1: ffffffffb5307940 (rcu_read_lock){....}-{1:3}, at: rcu_torture_init+0x1ec7/0x2370
 #2: ffffffffb536af40 (vmap_area_lock){+.+.}-{3:3}, at: find_vmap_area+0x1f/0x70
irq event stamp: 565512
hardirqs last  enabled at (565511): [<ffffffffb379b138>] __call_rcu_common+0x218/0x940
hardirqs last disabled at (565512): [<ffffffffb5804262>] rcu_torture_init+0x20b2/0x2370
softirqs last  enabled at (399112): [<ffffffffb36b2586>] __local_bh_enable_ip+0x126/0x170
softirqs last disabled at (399106): [<ffffffffb43fef59>] inet_register_protosw+0x9/0x1d0
Preemption disabled at:
[<ffffffffb58040c3>] rcu_torture_init+0x1f13/0x2370
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.5.0-rc4-rt2-yocto-preempt-rt+ torvalds#15
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xb0
 dump_stack+0x14/0x20
 __might_resched+0x1aa/0x280
 ? __pfx_rcu_torture_err_cb+0x10/0x10
 rt_spin_lock+0x53/0x130
 ? find_vmap_area+0x1f/0x70
 find_vmap_area+0x1f/0x70
 vmalloc_dump_obj+0x20/0x60
 mem_dump_obj+0x22/0x90
 __call_rcu_common+0x5bf/0x940
 ? debug_smp_processor_id+0x1b/0x30
 call_rcu_hurry+0x14/0x20
 rcu_torture_init+0x1f82/0x2370
 ? __pfx_rcu_torture_leak_cb+0x10/0x10
 ? __pfx_rcu_torture_leak_cb+0x10/0x10
 ? __pfx_rcu_torture_init+0x10/0x10
 do_one_initcall+0x6c/0x300
 ? debug_smp_processor_id+0x1b/0x30
 kernel_init_freeable+0x2b9/0x540
 ? __pfx_kernel_init+0x10/0x10
 kernel_init+0x1f/0x150
 ret_from_fork+0x40/0x50
 ? __pfx_kernel_init+0x10/0x10
 ret_from_fork_asm+0x1b/0x30
 </TASK>

The previous patch fixes this by using the deadlock-safe best-effort
version of find_vm_area.  However, in case of failure print the fact that
the pointer was a vmalloc pointer so that we print at least something.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 98f1808 ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: Zqiang <[email protected]>
Signed-off-by: Joel Fernandes (Google) <[email protected]>
Reported-by: Zhen Lei <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Sep 21, 2023
… delayed items

When running delayed items we are holding a delayed node's mutex and then
we will attempt to modify a subvolume btree to insert/update/delete the
delayed items. However if have an error during the insertions for example,
btrfs_insert_delayed_items() may return with a path that has locked extent
buffers (a leaf at the very least), and then we attempt to release the
delayed node at __btrfs_run_delayed_items(), which requires taking the
delayed node's mutex, causing an ABBA type of deadlock. This was reported
by syzbot and the lockdep splat is the following:

  WARNING: possible circular locking dependency detected
  6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0 Not tainted
  ------------------------------------------------------
  syz-executor.2/13257 is trying to acquire lock:
  ffff88801835c0c0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256

  but task is already holding lock:
  ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (btrfs-tree-00){++++}-{3:3}:
         __lock_release kernel/locking/lockdep.c:5475 [inline]
         lock_release+0x36f/0x9d0 kernel/locking/lockdep.c:5781
         up_write+0x79/0x580 kernel/locking/rwsem.c:1625
         btrfs_tree_unlock_rw fs/btrfs/locking.h:189 [inline]
         btrfs_unlock_up_safe+0x179/0x3b0 fs/btrfs/locking.c:239
         search_leaf fs/btrfs/ctree.c:1986 [inline]
         btrfs_search_slot+0x2511/0x2f80 fs/btrfs/ctree.c:2230
         btrfs_insert_empty_items+0x9c/0x180 fs/btrfs/ctree.c:4376
         btrfs_insert_delayed_item fs/btrfs/delayed-inode.c:746 [inline]
         btrfs_insert_delayed_items fs/btrfs/delayed-inode.c:824 [inline]
         __btrfs_commit_inode_delayed_items+0xd24/0x2410 fs/btrfs/delayed-inode.c:1111
         __btrfs_run_delayed_items+0x1db/0x430 fs/btrfs/delayed-inode.c:1153
         flush_space+0x269/0xe70 fs/btrfs/space-info.c:723
         btrfs_async_reclaim_metadata_space+0x106/0x350 fs/btrfs/space-info.c:1078
         process_one_work+0x92c/0x12c0 kernel/workqueue.c:2600
         worker_thread+0xa63/0x1210 kernel/workqueue.c:2751
         kthread+0x2b8/0x350 kernel/kthread.c:389
         ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145
         ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
         check_prev_add kernel/locking/lockdep.c:3142 [inline]
         check_prevs_add kernel/locking/lockdep.c:3261 [inline]
         validate_chain kernel/locking/lockdep.c:3876 [inline]
         __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
         lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
         __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
         __mutex_lock kernel/locking/mutex.c:747 [inline]
         mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
         __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256
         btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
         __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156
         btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276
         btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988
         vfs_fsync_range fs/sync.c:188 [inline]
         vfs_fsync fs/sync.c:202 [inline]
         do_fsync fs/sync.c:212 [inline]
         __do_sys_fsync fs/sync.c:220 [inline]
         __se_sys_fsync fs/sync.c:218 [inline]
         __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218
         do_syscall_x64 arch/x86/entry/common.c:50 [inline]
         do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
         entry_SYSCALL_64_after_hwframe+0x63/0xcd

  other info that might help us debug this:

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(btrfs-tree-00);
                                 lock(&delayed_node->mutex);
                                 lock(btrfs-tree-00);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by syz-executor.2/13257:
   #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: spin_unlock include/linux/spinlock.h:391 [inline]
   #0: ffff88802c1ee370 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0xb87/0xe00 fs/btrfs/transaction.c:287
   #1: ffff88802c1ee398 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0xbb2/0xe00 fs/btrfs/transaction.c:288
   #2: ffff88802a5ab8e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_lock+0x3c/0x2a0 fs/btrfs/locking.c:198

  stack backtrace:
  CPU: 0 PID: 13257 Comm: syz-executor.2 Not tainted 6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
   check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195
   check_prev_add kernel/locking/lockdep.c:3142 [inline]
   check_prevs_add kernel/locking/lockdep.c:3261 [inline]
   validate_chain kernel/locking/lockdep.c:3876 [inline]
   __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
   lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
   __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
   __mutex_lock kernel/locking/mutex.c:747 [inline]
   mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
   __btrfs_release_delayed_node+0x9a/0xaa0 fs/btrfs/delayed-inode.c:256
   btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline]
   __btrfs_run_delayed_items+0x2b5/0x430 fs/btrfs/delayed-inode.c:1156
   btrfs_commit_transaction+0x859/0x2ff0 fs/btrfs/transaction.c:2276
   btrfs_sync_file+0xf56/0x1330 fs/btrfs/file.c:1988
   vfs_fsync_range fs/sync.c:188 [inline]
   vfs_fsync fs/sync.c:202 [inline]
   do_fsync fs/sync.c:212 [inline]
   __do_sys_fsync fs/sync.c:220 [inline]
   __se_sys_fsync fs/sync.c:218 [inline]
   __x64_sys_fsync+0x196/0x1e0 fs/sync.c:218
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7f3ad047cae9
  Code: 28 00 00 00 75 (...)
  RSP: 002b:00007f3ad12510c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
  RAX: ffffffffffffffda RBX: 00007f3ad059bf80 RCX: 00007f3ad047cae9
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
  RBP: 00007f3ad04c847a R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 000000000000000b R14: 00007f3ad059bf80 R15: 00007ffe56af92f8
   </TASK>
  ------------[ cut here ]------------

Fix this by releasing the path before releasing the delayed node in the
error path at __btrfs_run_delayed_items().

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
CC: [email protected] # 4.14+
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
l1k pushed a commit that referenced this pull request Sep 21, 2023
macb_set_tx_clk() is called under a spinlock but itself calls clk_set_rate()
which can sleep. This results in:

| BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
| pps pps1: new PPS source ptp1
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 40, name: kworker/u4:3
| preempt_count: 1, expected: 0
| RCU nest depth: 0, expected: 0
| 4 locks held by kworker/u4:3/40:
|  #0: ffff000003409148
| macb ff0c000.ethernet: gem-ptp-timer ptp clock registered.
|  ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #1: ffff8000833cbdd8 ((work_completion)(&pl->resolve)){+.+.}-{0:0}, at: process_one_work+0x14c/0x51c
|  #2: ffff000004f01578 (&pl->state_mutex){+.+.}-{4:4}, at: phylink_resolve+0x44/0x4e8
|  #3: ffff000004f06f50 (&bp->lock){....}-{3:3}, at: macb_mac_link_up+0x40/0x2ac
| irq event stamp: 113998
| hardirqs last  enabled at (113997): [<ffff800080e8503c>] _raw_spin_unlock_irq+0x30/0x64
| hardirqs last disabled at (113998): [<ffff800080e84478>] _raw_spin_lock_irqsave+0xac/0xc8
| softirqs last  enabled at (113608): [<ffff800080010630>] __do_softirq+0x430/0x4e4
| softirqs last disabled at (113597): [<ffff80008001614c>] ____do_softirq+0x10/0x1c
| CPU: 0 PID: 40 Comm: kworker/u4:3 Not tainted 6.5.0-11717-g9355ce8b2f50-dirty torvalds#368
| Hardware name: ... ZynqMP ... (DT)
| Workqueue: events_power_efficient phylink_resolve
| Call trace:
|  dump_backtrace+0x98/0xf0
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x60/0xac
|  dump_stack+0x18/0x24
|  __might_resched+0x144/0x24c
|  __might_sleep+0x48/0x98
|  __mutex_lock+0x58/0x7b0
|  mutex_lock_nested+0x24/0x30
|  clk_prepare_lock+0x4c/0xa8
|  clk_set_rate+0x24/0x8c
|  macb_mac_link_up+0x25c/0x2ac
|  phylink_resolve+0x178/0x4e8
|  process_one_work+0x1ec/0x51c
|  worker_thread+0x1ec/0x3e4
|  kthread+0x120/0x124
|  ret_from_fork+0x10/0x20

The obvious fix is to move the call to macb_set_tx_clk() out of the
protected area. This seems safe as rx and tx are both disabled anyway at
this point.
It is however not entirely clear what the spinlock shall protect. It
could be the read-modify-write access to the NCFGR register, but this
is accessed in macb_set_rx_mode() and macb_set_rxcsum_feature() as well
without holding the spinlock. It could also be the register accesses
done in mog_init_rings() or macb_init_buffers(), but again these
functions are called without holding the spinlock in macb_hresp_error_task().
The locking seems fishy in this driver and it might deserve another look
before this patch is applied.

Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()")
Signed-off-by: Sascha Hauer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Sep 21, 2023
After commit 50f3034 ("igb: Enable SR-IOV after reinit"), removing
the igb module could hang or crash (depending on the machine) when the
module has been loaded with the max_vfs parameter set to some value != 0.

In case of one test machine with a dual port 82580, this hang occurred:

[  232.480687] igb 0000:41:00.1: removed PHC on enp65s0f1
[  233.093257] igb 0000:41:00.1: IOV Disabled
[  233.329969] pcieport 0000:40:01.0: AER: Multiple Uncorrected (Non-Fatal) err0
[  233.340302] igb 0000:41:00.0: PCIe Bus Error: severity=Uncorrected (Non-Fata)
[  233.352248] igb 0000:41:00.0:   device [8086:1516] error status/mask=00100000
[  233.361088] igb 0000:41:00.0:    [20] UnsupReq               (First)
[  233.368183] igb 0000:41:00.0: AER:   TLP Header: 40000001 0000040f cdbfc00c c
[  233.376846] igb 0000:41:00.1: PCIe Bus Error: severity=Uncorrected (Non-Fata)
[  233.388779] igb 0000:41:00.1:   device [8086:1516] error status/mask=00100000
[  233.397629] igb 0000:41:00.1:    [20] UnsupReq               (First)
[  233.404736] igb 0000:41:00.1: AER:   TLP Header: 40000001 0000040f cdbfc00c c
[  233.538214] pci 0000:41:00.1: AER: can't recover (no error_detected callback)
[  233.538401] igb 0000:41:00.0: removed PHC on enp65s0f0
[  233.546197] pcieport 0000:40:01.0: AER: device recovery failed
[  234.157244] igb 0000:41:00.0: IOV Disabled
[  371.619705] INFO: task irq/35-aerdrv:257 blocked for more than 122 seconds.
[  371.627489]       Not tainted 6.4.0-dirty #2
[  371.632257] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this.
[  371.641000] task:irq/35-aerdrv   state:D stack:0     pid:257   ppid:2      f0
[  371.650330] Call Trace:
[  371.653061]  <TASK>
[  371.655407]  __schedule+0x20e/0x660
[  371.659313]  schedule+0x5a/0xd0
[  371.662824]  schedule_preempt_disabled+0x11/0x20
[  371.667983]  __mutex_lock.constprop.0+0x372/0x6c0
[  371.673237]  ? __pfx_aer_root_reset+0x10/0x10
[  371.678105]  report_error_detected+0x25/0x1c0
[  371.682974]  ? __pfx_report_normal_detected+0x10/0x10
[  371.688618]  pci_walk_bus+0x72/0x90
[  371.692519]  pcie_do_recovery+0xb2/0x330
[  371.696899]  aer_process_err_devices+0x117/0x170
[  371.702055]  aer_isr+0x1c0/0x1e0
[  371.705661]  ? __set_cpus_allowed_ptr+0x54/0xa0
[  371.710723]  ? __pfx_irq_thread_fn+0x10/0x10
[  371.715496]  irq_thread_fn+0x20/0x60
[  371.719491]  irq_thread+0xe6/0x1b0
[  371.723291]  ? __pfx_irq_thread_dtor+0x10/0x10
[  371.728255]  ? __pfx_irq_thread+0x10/0x10
[  371.732731]  kthread+0xe2/0x110
[  371.736243]  ? __pfx_kthread+0x10/0x10
[  371.740430]  ret_from_fork+0x2c/0x50
[  371.744428]  </TASK>

The reproducer was a simple script:

  #!/bin/sh
  for i in `seq 1 5`; do
    modprobe -rv igb
    modprobe -v igb max_vfs=1
    sleep 1
    modprobe -rv igb
  done

It turned out that this could only be reproduce on 82580 (quad and
dual-port), but not on 82576, i350 and i210.  Further debugging showed
that igb_enable_sriov()'s call to pci_enable_sriov() is failing, because
dev->is_physfn is 0 on 82580.

Prior to commit 50f3034 ("igb: Enable SR-IOV after reinit"),
igb_enable_sriov() jumped into the "err_out" cleanup branch.  After this
commit it only returned the error code.

So the cleanup didn't take place, and the incorrect VF setup in the
igb_adapter structure fooled the igb driver into assuming that VFs have
been set up where no VF actually existed.

Fix this problem by cleaning up again if pci_enable_sriov() fails.

Fixes: 50f3034 ("igb: Enable SR-IOV after reinit")
Signed-off-by: Corinna Vinschen <[email protected]>
Reviewed-by: Akihiko Odaki <[email protected]>
Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
When using --Summary mode, added MSRs in raw mode always
print zeros. Print the actual register contents.

Example, with patch:

note the added column:
--add msr0x64f,u32,package,raw,REASON

Where:

0x64F is MSR_CORE_PERF_LIMIT_REASONS

Busy%   Bzy_MHz PkgTmp  PkgWatt CorWatt     REASON
0.00    4800    35      1.42    0.76    0x00000000
0.00    4801    34      1.42    0.76    0x00000000
80.08   4531    66      108.17  107.52  0x08000000
98.69   4530    66      133.21  132.54  0x08000000
99.28   4505    66      128.26  127.60  0x0c000400
99.65   4486    68      124.91  124.25  0x0c000400
99.63   4483    68      124.90  124.25  0x0c000400
79.34   4481    41      99.80   99.13   0x0c000000
0.00    4801    41      1.40    0.73    0x0c000000

Where, for the test processor (i5-10600K):

PKG Limit #1: 125.000 Watts, 8.000000 sec
MSR bit 26 = log; bit 10 = status

PKG Limit #2: 136.000 Watts, 0.002441 sec
MSR bit 27 = log; bit 11 = status

Example, without patch:

Busy%   Bzy_MHz PkgTmp  PkgWatt CorWatt     REASON
0.01    4800    35      1.43    0.77    0x00000000
0.00    4801    35      1.39    0.73    0x00000000
83.49   4531    66      112.71  112.06  0x00000000
98.69   4530    68      133.35  132.69  0x00000000
99.31   4500    67      127.96  127.30  0x00000000
99.63   4483    69      124.91  124.25  0x00000000
99.61   4481    69      124.90  124.25  0x00000000
99.61   4481    71      124.92  124.25  0x00000000
59.35   4479    42      75.03   74.37   0x00000000
0.00    4800    42      1.39    0.73    0x00000000
0.00    4801    42      1.42    0.76    0x00000000

c000000

[lenb: simplified patch to apply only to package scope]

Signed-off-by: Doug Smythies <[email protected]>
Signed-off-by: Len Brown <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:

1) A swapin error can have resulted in a poisoned swap entry in the
   shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
   will result in an out-of-bounds access to swapper_spaces[].

   Validate the entry with non_swap_entry() before going further.

2) When we find a valid swap entry in the shmem's inode, the shadow
   entry in the swapcache might not exist yet: swap IO is still in
   progress and we're before __remove_mapping; swapin, invalidation,
   or swapoff have removed the shadow from swapcache after we saw the
   shmem swap entry.

   This will send a NULL to workingset_test_recent(). The latter
   purely operates on pointer bits, so it won't crash - node 0, memcg
   ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
   bogus test. In theory that could result in a false "recently
   evicted" count.

   Such a false positive wouldn't be the end of the world. But for
   code clarity and (future) robustness, be explicit about this case.

   Bail on get_shadow_from_swap_cache() returning NULL.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: cf264e1 ("cachestat: implement cachestat syscall")
Signed-off-by: Johannes Weiner <[email protected]>
Reported-by: Chengming Zhou <[email protected]>	[Bug #1]
Reported-by: Jann Horn <[email protected]>		[Bug #2]
Reviewed-by: Chengming Zhou <[email protected]>
Reviewed-by: Nhat Pham <[email protected]>
Cc: <[email protected]>				[v6.5+]
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
Use down_read_nested() to avoid the warning.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 867a43a ("userfaultfd: use per-vma locks in userfaultfd operations")
Reported-by: [email protected]
Signed-off-by: Lokesh Gidra <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Brian Geffon <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Jann Horn <[email protected]> [Bug #2]
Cc: Kalesh Singh <[email protected]>
Cc: Lokesh Gidra <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Nicolas Geoffray <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
An errant disk backup on my desktop got into debugfs and triggered the
following deadlock scenario in the amdgpu debugfs files. The machine
also hard-resets immediately after those lines are printed (although I
wasn't able to reproduce that part when reading by hand):

[ 1318.016074][ T1082] ======================================================
[ 1318.016607][ T1082] WARNING: possible circular locking dependency detected
[ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 torvalds#17 Not tainted
[ 1318.017598][ T1082] ------------------------------------------------------
[ 1318.018096][ T1082] tar/1082 is trying to acquire lock:
[ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80
[ 1318.019084][ T1082]
[ 1318.019084][ T1082] but task is already holding lock:
[ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.020607][ T1082]
[ 1318.020607][ T1082] which lock already depends on the new lock.
[ 1318.020607][ T1082]
[ 1318.022081][ T1082]
[ 1318.022081][ T1082] the existing dependency chain (in reverse order) is:
[ 1318.023083][ T1082]
[ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}:
[ 1318.024114][ T1082]        __ww_mutex_lock.constprop.0+0xe0/0x12f0
[ 1318.024639][ T1082]        ww_mutex_lock+0x32/0x90
[ 1318.025161][ T1082]        dma_resv_lockdep+0x18a/0x330
[ 1318.025683][ T1082]        do_one_initcall+0x6a/0x350
[ 1318.026210][ T1082]        kernel_init_freeable+0x1a3/0x310
[ 1318.026728][ T1082]        kernel_init+0x15/0x1a0
[ 1318.027242][ T1082]        ret_from_fork+0x2c/0x40
[ 1318.027759][ T1082]        ret_from_fork_asm+0x11/0x20
[ 1318.028281][ T1082]
[ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}:
[ 1318.029297][ T1082]        dma_resv_lockdep+0x16c/0x330
[ 1318.029790][ T1082]        do_one_initcall+0x6a/0x350
[ 1318.030263][ T1082]        kernel_init_freeable+0x1a3/0x310
[ 1318.030722][ T1082]        kernel_init+0x15/0x1a0
[ 1318.031168][ T1082]        ret_from_fork+0x2c/0x40
[ 1318.031598][ T1082]        ret_from_fork_asm+0x11/0x20
[ 1318.032011][ T1082]
[ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}:
[ 1318.032778][ T1082]        __lock_acquire+0x14bf/0x2680
[ 1318.033141][ T1082]        lock_acquire+0xcd/0x2c0
[ 1318.033487][ T1082]        __might_fault+0x58/0x80
[ 1318.033814][ T1082]        amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu]
[ 1318.034181][ T1082]        full_proxy_read+0x55/0x80
[ 1318.034487][ T1082]        vfs_read+0xa7/0x360
[ 1318.034788][ T1082]        ksys_read+0x70/0xf0
[ 1318.035085][ T1082]        do_syscall_64+0x94/0x180
[ 1318.035375][ T1082]        entry_SYSCALL_64_after_hwframe+0x46/0x4e
[ 1318.035664][ T1082]
[ 1318.035664][ T1082] other info that might help us debug this:
[ 1318.035664][ T1082]
[ 1318.036487][ T1082] Chain exists of:
[ 1318.036487][ T1082]   &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[ 1318.036487][ T1082]
[ 1318.037310][ T1082]  Possible unsafe locking scenario:
[ 1318.037310][ T1082]
[ 1318.037838][ T1082]        CPU0                    CPU1
[ 1318.038101][ T1082]        ----                    ----
[ 1318.038350][ T1082]   lock(reservation_ww_class_mutex);
[ 1318.038590][ T1082]                                lock(reservation_ww_class_acquire);
[ 1318.038839][ T1082]                                lock(reservation_ww_class_mutex);
[ 1318.039083][ T1082]   rlock(&mm->mmap_lock);
[ 1318.039328][ T1082]
[ 1318.039328][ T1082]  *** DEADLOCK ***
[ 1318.039328][ T1082]
[ 1318.040029][ T1082] 1 lock held by tar/1082:
[ 1318.040259][ T1082]  #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.040560][ T1082]
[ 1318.040560][ T1082] stack backtrace:
[ 1318.041053][ T1082] CPU: 22 PID: 1082 Comm: tar Not tainted 6.8.0-rc7-00015-ge0c8221b72c0 torvalds#17 3316c85d50e282c5643b075d1f01a4f6365e39c2
[ 1318.041329][ T1082] Hardware name: Gigabyte Technology Co., Ltd. B650 AORUS PRO AX/B650 AORUS PRO AX, BIOS F20 12/14/2023
[ 1318.041614][ T1082] Call Trace:
[ 1318.041895][ T1082]  <TASK>
[ 1318.042175][ T1082]  dump_stack_lvl+0x4a/0x80
[ 1318.042460][ T1082]  check_noncircular+0x145/0x160
[ 1318.042743][ T1082]  __lock_acquire+0x14bf/0x2680
[ 1318.043022][ T1082]  lock_acquire+0xcd/0x2c0
[ 1318.043301][ T1082]  ? __might_fault+0x40/0x80
[ 1318.043580][ T1082]  ? __might_fault+0x40/0x80
[ 1318.043856][ T1082]  __might_fault+0x58/0x80
[ 1318.044131][ T1082]  ? __might_fault+0x40/0x80
[ 1318.044408][ T1082]  amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu 8fe2afaa910cbd7654c8cab23563a94d6caebaab]
[ 1318.044749][ T1082]  full_proxy_read+0x55/0x80
[ 1318.045042][ T1082]  vfs_read+0xa7/0x360
[ 1318.045333][ T1082]  ksys_read+0x70/0xf0
[ 1318.045623][ T1082]  do_syscall_64+0x94/0x180
[ 1318.045913][ T1082]  ? do_syscall_64+0xa0/0x180
[ 1318.046201][ T1082]  ? lockdep_hardirqs_on+0x7d/0x100
[ 1318.046487][ T1082]  ? do_syscall_64+0xa0/0x180
[ 1318.046773][ T1082]  ? do_syscall_64+0xa0/0x180
[ 1318.047057][ T1082]  ? do_syscall_64+0xa0/0x180
[ 1318.047337][ T1082]  ? do_syscall_64+0xa0/0x180
[ 1318.047611][ T1082]  entry_SYSCALL_64_after_hwframe+0x46/0x4e
[ 1318.047887][ T1082] RIP: 0033:0x7f480b70a39d
[ 1318.048162][ T1082] Code: 91 ba 0d 00 f7 d8 64 89 02 b8 ff ff ff ff eb b2 e8 18 a3 01 00 0f 1f 84 00 00 00 00 00 80 3d a9 3c 0e 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 53 48 83
[ 1318.048769][ T1082] RSP: 002b:00007ffde77f5c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 1318.049083][ T1082] RAX: ffffffffffffffda RBX: 0000000000000800 RCX: 00007f480b70a39d
[ 1318.049392][ T1082] RDX: 0000000000000800 RSI: 000055c9f2120c00 RDI: 0000000000000008
[ 1318.049703][ T1082] RBP: 0000000000000800 R08: 000055c9f2120a94 R09: 0000000000000007
[ 1318.050011][ T1082] R10: 0000000000000000 R11: 0000000000000246 R12: 000055c9f2120c00
[ 1318.050324][ T1082] R13: 0000000000000008 R14: 0000000000000008 R15: 0000000000000800
[ 1318.050638][ T1082]  </TASK>

amdgpu_debugfs_mqd_read() holds a reservation when it calls
put_user(), which may fault and acquire the mmap_sem. This violates
the established locking order.

Bounce the mqd data through a kernel buffer to get put_user() out of
the illegal section.

Fixes: 445d85e ("drm/amdgpu: add debugfs interface for reading MQDs")
Cc: [email protected] # v6.5+
Reviewed-by: Shashank Sharma <[email protected]>
Signed-off-by: Johannes Weiner <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
The driver creates /sys/kernel/debug/dri/0/mob_ttm even when the
corresponding ttm_resource_manager is not allocated.
This leads to a crash when trying to read from this file.

Add a check to create mob_ttm, system_mob_ttm, and gmr_ttm debug file
only when the corresponding ttm_resource_manager is allocated.

crash> bt
PID: 3133409  TASK: ffff8fe4834a5000  CPU: 3    COMMAND: "grep"
 #0 [ffffb954506b3b20] machine_kexec at ffffffffb2a6bec3
 #1 [ffffb954506b3b78] __crash_kexec at ffffffffb2bb598a
 #2 [ffffb954506b3c38] crash_kexec at ffffffffb2bb68c1
 #3 [ffffb954506b3c50] oops_end at ffffffffb2a2a9b1
 #4 [ffffb954506b3c70] no_context at ffffffffb2a7e913
 #5 [ffffb954506b3cc8] __bad_area_nosemaphore at ffffffffb2a7ec8c
 #6 [ffffb954506b3d10] do_page_fault at ffffffffb2a7f887
 torvalds#7 [ffffb954506b3d40] page_fault at ffffffffb360116e
    [exception RIP: ttm_resource_manager_debug+0x11]
    RIP: ffffffffc04afd11  RSP: ffffb954506b3df0  RFLAGS: 00010246
    RAX: ffff8fe41a6d1200  RBX: 0000000000000000  RCX: 0000000000000940
    RDX: 0000000000000000  RSI: ffffffffc04b4338  RDI: 0000000000000000
    RBP: ffffb954506b3e08   R8: ffff8fee3ffad000   R9: 0000000000000000
    R10: ffff8fe41a76a000  R11: 0000000000000001  R12: 00000000ffffffff
    R13: 0000000000000001  R14: ffff8fe5bb6f3900  R15: ffff8fe41a6d1200
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 torvalds#8 [ffffb954506b3e00] ttm_resource_manager_show at ffffffffc04afde7 [ttm]
 torvalds#9 [ffffb954506b3e30] seq_read at ffffffffb2d8f9f3
    RIP: 00007f4c4eda8985  RSP: 00007ffdbba9e9f8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 000000000037e000  RCX: 00007f4c4eda8985
    RDX: 000000000037e000  RSI: 00007f4c41573000  RDI: 0000000000000003
    RBP: 000000000037e000   R8: 0000000000000000   R9: 000000000037fe30
    R10: 0000000000000000  R11: 0000000000000246  R12: 00007f4c41573000
    R13: 0000000000000003  R14: 00007f4c41572010  R15: 0000000000000003
    ORIG_RAX: 0000000000000000  CS: 0033  SS: 002b

Signed-off-by: Jocelyn Falempe <[email protected]>
Fixes: af4a25b ("drm/vmwgfx: Add debugfs entries for various ttm resource managers")
Cc: <[email protected]>
Reviewed-by: Zack Rusin <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
l1k pushed a commit that referenced this pull request Apr 14, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 reject destroy chain command to delete device hooks in netdev
         family, hence, only delchain commands are allowed.

Patch #2 reject table flag update interference with netdev basechain
	 hook updates, this can leave hooks in inconsistent
	 registration/unregistration state.

Patch #3 do not unregister netdev basechain hooks if table is dormant.
	 Otherwise, splat with double unregistration is possible.

Patch #4 fixes Kconfig to allow to restore IP_NF_ARPTABLES,
	 from Kuniyuki Iwashima.

There are a more fixes still in progress on my side that need more work.

* tag 'nf-24-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: arptables: Select NETFILTER_FAMILY_ARP when building arp_tables.c
  netfilter: nf_tables: skip netdev hook unregistration if table is dormant
  netfilter: nf_tables: reject table flag and netdev basechain updates
  netfilter: nf_tables: reject destroy command to remove basechain hooks
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
qdisc_tree_reduce_backlog() is called with the qdisc lock held,
not RTNL.

We must use qdisc_lookup_rcu() instead of qdisc_lookup()

syzbot reported:

WARNING: suspicious RCU usage
6.1.74-syzkaller #0 Not tainted
-----------------------------
net/sched/sch_api.c:305 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by udevd/1142:
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: net_tx_action+0x64a/0x970 net/core/dev.c:5282
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: net_tx_action+0x754/0x970 net/core/dev.c:5297
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: qdisc_tree_reduce_backlog+0x84/0x580 net/sched/sch_api.c:792

stack backtrace:
CPU: 1 PID: 1142 Comm: udevd Not tainted 6.1.74-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
  [<ffffffff85b85f14>] __dump_stack lib/dump_stack.c:88 [inline]
  [<ffffffff85b85f14>] dump_stack_lvl+0x1b1/0x28f lib/dump_stack.c:106
  [<ffffffff85b86007>] dump_stack+0x15/0x1e lib/dump_stack.c:113
  [<ffffffff81802299>] lockdep_rcu_suspicious+0x1b9/0x260 kernel/locking/lockdep.c:6592
  [<ffffffff84f0054c>] qdisc_lookup+0xac/0x6f0 net/sched/sch_api.c:305
  [<ffffffff84f037c3>] qdisc_tree_reduce_backlog+0x243/0x580 net/sched/sch_api.c:811
  [<ffffffff84f5b78c>] pfifo_tail_enqueue+0x32c/0x4b0 net/sched/sch_fifo.c:51
  [<ffffffff84fbcf63>] qdisc_enqueue include/net/sch_generic.h:833 [inline]
  [<ffffffff84fbcf63>] netem_dequeue+0xeb3/0x15d0 net/sched/sch_netem.c:723
  [<ffffffff84eecab9>] dequeue_skb net/sched/sch_generic.c:292 [inline]
  [<ffffffff84eecab9>] qdisc_restart net/sched/sch_generic.c:397 [inline]
  [<ffffffff84eecab9>] __qdisc_run+0x249/0x1e60 net/sched/sch_generic.c:415
  [<ffffffff84d7aa96>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125
  [<ffffffff84d85d29>] net_tx_action+0x7c9/0x970 net/core/dev.c:5313
  [<ffffffff85e002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:616
  [<ffffffff81568bca>] invoke_softirq kernel/softirq.c:447 [inline]
  [<ffffffff81568bca>] __irq_exit_rcu+0xca/0x230 kernel/softirq.c:700
  [<ffffffff81568ae9>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:712
  [<ffffffff85b89f52>] sysvec_apic_timer_interrupt+0x42/0x90 arch/x86/kernel/apic/apic.c:1107
  [<ffffffff85c00ccb>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:656

Fixes: d636fc5 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
Reported-by: syzbot <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Acked-by: Jamal Hadi Salim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 unlike early commit path stage which triggers a call to abort,
         an explicit release of the batch is required on abort, otherwise
         mutex is released and commit_list remains in place.

Patch #2 release mutex after nft_gc_seq_end() in commit path, otherwise
         async GC worker could collect expired objects.

Patch #3 flush pending destroy work in module removal path, otherwise UaF
         is possible.

Patch #4 and #6 restrict the table dormant flag with basechain updates
	 to fix state inconsistency in the hook registration.

Patch #5 adds missing RCU read side lock to flowtable type to avoid races
	 with module removal.

* tag 'nf-24-04-04' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: discard table flag update with pending basechain deletion
  netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
  netfilter: nf_tables: reject new basechain after table flag update
  netfilter: nf_tables: flush pending destroy work before exit_net release
  netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
  netfilter: nf_tables: release batch on table validation from abort path
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
The following warning appears when using ftrace:

[89855.443413] RCU not on for: arch_cpu_idle+0x0/0x1c
[89855.445640] WARNING: CPU: 5 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x208/0x228
[89855.445824] Modules linked in: xt_conntrack(E) nft_chain_nat(E) xt_MASQUERADE(E) nf_conntrack_netlink(E) xt_addrtype(E) nft_compat(E) nf_tables(E) nfnetlink(E) br_netfilter(E) cfg80211(E) nls_iso8859_1(E) ofpart(E) redboot(E) cmdlinepart(E) cfi_cmdset_0001(E) virtio_net(E) cfi_probe(E) cfi_util(E) 9pnet_virtio(E) gen_probe(E) net_failover(E) virtio_rng(E) failover(E) 9pnet(E) physmap(E) map_funcs(E) chipreg(E) mtd(E) uio_pdrv_genirq(E) uio(E) dm_multipath(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) drm(E) efi_pstore(E) backlight(E) ip_tables(E) x_tables(E) raid10(E) raid456(E) async_raid6_recov(E) async_memcpy(E) async_pq(E) async_xor(E) xor(E) async_tx(E) raid6_pq(E) raid1(E) raid0(E) virtio_blk(E)
[89855.451563] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G            E      6.8.0-rc6ubuntu-defconfig #2
[89855.451726] Hardware name: riscv-virtio,qemu (DT)
[89855.451899] epc : arch_ftrace_ops_list_func+0x208/0x228
[89855.452016]  ra : arch_ftrace_ops_list_func+0x208/0x228
[89855.452119] epc : ffffffff8016b216 ra : ffffffff8016b216 sp : ffffaf808090fdb0
[89855.452171]  gp : ffffffff827c7680 tp : ffffaf808089ad40 t0 : ffffffff800c0dd8
[89855.452216]  t1 : 0000000000000001 t2 : 0000000000000000 s0 : ffffaf808090fe30
[89855.452306]  s1 : 0000000000000000 a0 : 0000000000000026 a1 : ffffffff82cd6ac8
[89855.452423]  a2 : ffffffff800458c8 a3 : ffffaf80b1870640 a4 : 0000000000000000
[89855.452646]  a5 : 0000000000000000 a6 : 00000000ffffffff a7 : ffffffffffffffff
[89855.452698]  s2 : ffffffff82766872 s3 : ffffffff80004caa s4 : ffffffff80ebea90
[89855.452743]  s5 : ffffaf808089bd40 s6 : 8000000a00006e00 s7 : 0000000000000008
[89855.452787]  s8 : 0000000000002000 s9 : 0000000080043700 s10: 0000000000000000
[89855.452831]  s11: 0000000000000000 t3 : 0000000000100000 t4 : 0000000000000064
[89855.452874]  t5 : 000000000000000c t6 : ffffaf80b182dbfc
[89855.452929] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
[89855.453053] [<ffffffff8016b216>] arch_ftrace_ops_list_func+0x208/0x228
[89855.453191] [<ffffffff8000e082>] ftrace_call+0x8/0x22
[89855.453265] [<ffffffff800a149c>] do_idle+0x24c/0x2ca
[89855.453357] [<ffffffff8000da54>] return_to_handler+0x0/0x26
[89855.453429] [<ffffffff8000b716>] smp_callin+0x92/0xb6
[89855.453785] ---[ end trace 0000000000000000 ]---

To fix this, mark arch_cpu_idle() as noinstr, like it is done in commit
a9cbc1b ("s390/idle: mark arch_cpu_idle() noinstr").

Reported-by: Evgenii Shatokhin <[email protected]>
Closes: https://lore.kernel.org/linux-riscv/[email protected]/
Fixes: cfbc4f8 ("riscv: Select ARCH_WANTS_NO_INSTR")
Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Andy Chiu <[email protected]>
Tested-by: Andy Chiu <[email protected]>
Acked-by: Puranjay Mohan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
…git/netfilter/nf

netfilter pull request 24-04-11

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patches #1 and #2 add missing rcu read side lock when iterating over
expression and object type list which could race with module removal.

Patch #3 prevents promisc packet from visiting the bridge/input hook
	 to amend a recent fix to address conntrack confirmation race
	 in br_netfilter and nf_conntrack_bridge.

Patch #4 adds and uses iterate decorator type to fetch the current
	 pipapo set backend datastructure view when netlink dumps the
	 set elements.

Patch #5 fixes removal of duplicate elements in the pipapo set backend.

Patch #6 flowtable validates pppoe header before accessing it.

Patch torvalds#7 fixes flowtable datapath for pppoe packets, otherwise lookup
         fails and pppoe packets follow classic path.
====================

Signed-off-by: David S. Miller <[email protected]>
l1k pushed a commit that referenced this pull request Apr 14, 2024
When disabling aRFS under the `priv->state_lock`, any scheduled
aRFS works are canceled using the `cancel_work_sync` function,
which waits for the work to end if it has already started.
However, while waiting for the work handler, the handler will
try to acquire the `state_lock` which is already acquired.

The worker acquires the lock to delete the rules if the state
is down, which is not the worker's responsibility since
disabling aRFS deletes the rules.

Add an aRFS state variable, which indicates whether the aRFS is
enabled and prevent adding rules when the aRFS is disabled.

Kernel log:

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc4_net_next_mlx5_5483eb2 #1 Tainted: G          I
------------------------------------------------------
ethtool/386089 is trying to acquire lock:
ffff88810f21ce68 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}, at: __flush_work+0x74/0x4e0

but task is already holding lock:
ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&priv->state_lock){+.+.}-{3:3}:
       __mutex_lock+0x80/0xc90
       arfs_handle_work+0x4b/0x3b0 [mlx5_core]
       process_one_work+0x1dc/0x4a0
       worker_thread+0x1bf/0x3c0
       kthread+0xd7/0x100
       ret_from_fork+0x2d/0x50
       ret_from_fork_asm+0x11/0x20

-> #0 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}:
       __lock_acquire+0x17b4/0x2c80
       lock_acquire+0xd0/0x2b0
       __flush_work+0x7a/0x4e0
       __cancel_work_timer+0x131/0x1c0
       arfs_del_rules+0x143/0x1e0 [mlx5_core]
       mlx5e_arfs_disable+0x1b/0x30 [mlx5_core]
       mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core]
       ethnl_set_channels+0x28f/0x3b0
       ethnl_default_set_doit+0xec/0x240
       genl_family_rcv_msg_doit+0xd0/0x120
       genl_rcv_msg+0x188/0x2c0
       netlink_rcv_skb+0x54/0x100
       genl_rcv+0x24/0x40
       netlink_unicast+0x1a1/0x270
       netlink_sendmsg+0x214/0x460
       __sock_sendmsg+0x38/0x60
       __sys_sendto+0x113/0x170
       __x64_sys_sendto+0x20/0x30
       do_syscall_64+0x40/0xe0
       entry_SYSCALL_64_after_hwframe+0x46/0x4e

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&priv->state_lock);
                               lock((work_completion)(&rule->arfs_work));
                               lock(&priv->state_lock);
  lock((work_completion)(&rule->arfs_work));

 *** DEADLOCK ***

3 locks held by ethtool/386089:
 #0: ffffffff82ea7210 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40
 #1: ffffffff82e94c88 (rtnl_mutex){+.+.}-{3:3}, at: ethnl_default_set_doit+0xd3/0x240
 #2: ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core]

stack backtrace:
CPU: 15 PID: 386089 Comm: ethtool Tainted: G          I        6.7.0-rc4_net_next_mlx5_5483eb2 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x60/0xa0
 check_noncircular+0x144/0x160
 __lock_acquire+0x17b4/0x2c80
 lock_acquire+0xd0/0x2b0
 ? __flush_work+0x74/0x4e0
 ? save_trace+0x3e/0x360
 ? __flush_work+0x74/0x4e0
 __flush_work+0x7a/0x4e0
 ? __flush_work+0x74/0x4e0
 ? __lock_acquire+0xa78/0x2c80
 ? lock_acquire+0xd0/0x2b0
 ? mark_held_locks+0x49/0x70
 __cancel_work_timer+0x131/0x1c0
 ? mark_held_locks+0x49/0x70
 arfs_del_rules+0x143/0x1e0 [mlx5_core]
 mlx5e_arfs_disable+0x1b/0x30 [mlx5_core]
 mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core]
 ethnl_set_channels+0x28f/0x3b0
 ethnl_default_set_doit+0xec/0x240
 genl_family_rcv_msg_doit+0xd0/0x120
 genl_rcv_msg+0x188/0x2c0
 ? ethnl_ops_begin+0xb0/0xb0
 ? genl_family_rcv_msg_dumpit+0xf0/0xf0
 netlink_rcv_skb+0x54/0x100
 genl_rcv+0x24/0x40
 netlink_unicast+0x1a1/0x270
 netlink_sendmsg+0x214/0x460
 __sock_sendmsg+0x38/0x60
 __sys_sendto+0x113/0x170
 ? do_user_addr_fault+0x53f/0x8f0
 __x64_sys_sendto+0x20/0x30
 do_syscall_64+0x40/0xe0
 entry_SYSCALL_64_after_hwframe+0x46/0x4e
 </TASK>

Fixes: 45bf454 ("net/mlx5e: Enabling aRFS mechanism")
Signed-off-by: Carolina Jubran <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
l1k pushed a commit that referenced this pull request Jun 29, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 syzbot reports that nf_reinject() could be called without
         rcu_read_lock() when flushing pending packets at nfnetlink
         queue removal, from Eric Dumazet.

Patch #2 flushes ipset list:set when canceling garbage collection to
         reference to other lists to fix a race, from Jozsef Kadlecsik.

Patch #3 restores q-in-q matching with nft_payload by reverting
         f6ae9f1 ("netfilter: nft_payload: add C-VLAN support").

Patch #4 fixes vlan mangling in skbuff when vlan offload is present
         in skbuff, without this patch nft_payload corrupts packets
         in this case.

Patch #5 fixes possible nul-deref in tproxy no IP address is found in
         netdevice, reported by syzbot and patch from Florian Westphal.

Patch #6 removes a superfluous restriction which prevents loose fib
         lookups from input and forward hooks, from Eric Garver.

My assessment is that patches #1, #2 and #5 address possible kernel
crash, anything else in this batch fixes broken features.

netfilter pull request 24-05-29

* tag 'nf-24-05-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_fib: allow from forward/input without iif selector
  netfilter: tproxy: bail out if IP has been disabled on the device
  netfilter: nft_payload: skbuff vlan metadata mangle support
  netfilter: nft_payload: restore vlan q-in-q match support
  netfilter: ipset: Add list flush to cancel_gc
  netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu()
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
We found a timeout problem with the pldm command on our system.  The
reason is that the MCTP-I3C driver has a race condition when receiving
multiple-packet messages in multi-thread, resulting in a wrong packet
order problem.

We identified this problem by adding a debug message to the
mctp_i3c_read function.

According to the MCTP spec, a multiple-packet message must be composed
in sequence, and if there is a wrong sequence, the whole message will be
discarded and wait for the next SOM.
For example, SOM → Pkt Seq #2 → Pkt Seq #1 → Pkt Seq #3 → EOM.

Therefore, we try to solve this problem by adding a mutex to the
mctp_i3c_read function.  Before the modification, when a command
requesting a multiple-packet message response is sent consecutively, an
error usually occurs within 100 loops.  After the mutex, it can go
through 40000 loops without any error, and it seems to run well.

Fixes: c8755b2 ("mctp i3c: MCTP I3C driver")
Signed-off-by: Leo Yang <[email protected]>
Link: https://patch.msgid.link/[email protected]
[[email protected]: dropped already answered question from changelog]
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ torvalds#69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ torvalds#69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
This commit addresses a circular locking dependency issue within the GFX
isolation mechanism. The problem was identified by a warning indicating
a potential deadlock due to inconsistent lock acquisition order.

- The `amdgpu_gfx_enforce_isolation_ring_begin_use` and
  `amdgpu_gfx_enforce_isolation_ring_end_use` functions previously
  acquired `enforce_isolation_mutex` and called `amdgpu_gfx_kfd_sch_ctrl`,
  leading to potential deadlocks. ie., If `amdgpu_gfx_kfd_sch_ctrl` is
  called while `enforce_isolation_mutex` is held, and
  `amdgpu_gfx_enforce_isolation_handler` is called while `kfd_sch_mutex` is
  held, it can create a circular dependency.

By ensuring consistent lock usage, this fix resolves the issue:

[  606.297333] ======================================================
[  606.297343] WARNING: possible circular locking dependency detected
[  606.297353] 6.10.0-amd-mlkd-610-311224-lof torvalds#19 Tainted: G           OE
[  606.297365] ------------------------------------------------------
[  606.297375] kworker/u96:3/3825 is trying to acquire lock:
[  606.297385] ffff9aa64e431cb8 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}, at: __flush_work+0x232/0x610
[  606.297413]
               but task is already holding lock:
[  606.297423] ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.297725]
               which lock already depends on the new lock.

[  606.297738]
               the existing dependency chain (in reverse order) is:
[  606.297749]
               -> #2 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}:
[  606.297765]        __mutex_lock+0x85/0x930
[  606.297776]        mutex_lock_nested+0x1b/0x30
[  606.297786]        amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.298007]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.298225]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.298412]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.298603]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.298866]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.298880]        process_one_work+0x21e/0x680
[  606.298890]        worker_thread+0x190/0x350
[  606.298899]        kthread+0xe7/0x120
[  606.298908]        ret_from_fork+0x3c/0x60
[  606.298919]        ret_from_fork_asm+0x1a/0x30
[  606.298929]
               -> #1 (&adev->enforce_isolation_mutex){+.+.}-{3:3}:
[  606.298947]        __mutex_lock+0x85/0x930
[  606.298956]        mutex_lock_nested+0x1b/0x30
[  606.298966]        amdgpu_gfx_enforce_isolation_handler+0x87/0x370 [amdgpu]
[  606.299190]        process_one_work+0x21e/0x680
[  606.299199]        worker_thread+0x190/0x350
[  606.299208]        kthread+0xe7/0x120
[  606.299217]        ret_from_fork+0x3c/0x60
[  606.299227]        ret_from_fork_asm+0x1a/0x30
[  606.299236]
               -> #0 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}:
[  606.299257]        __lock_acquire+0x16f9/0x2810
[  606.299267]        lock_acquire+0xd1/0x300
[  606.299276]        __flush_work+0x250/0x610
[  606.299286]        cancel_delayed_work_sync+0x71/0x80
[  606.299296]        amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.299509]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.299723]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.299909]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.300101]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.300355]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.300369]        process_one_work+0x21e/0x680
[  606.300378]        worker_thread+0x190/0x350
[  606.300387]        kthread+0xe7/0x120
[  606.300396]        ret_from_fork+0x3c/0x60
[  606.300406]        ret_from_fork_asm+0x1a/0x30
[  606.300416]
               other info that might help us debug this:

[  606.300428] Chain exists of:
                 (work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work) --> &adev->enforce_isolation_mutex --> &adev->gfx.kfd_sch_mutex

[  606.300458]  Possible unsafe locking scenario:

[  606.300468]        CPU0                    CPU1
[  606.300476]        ----                    ----
[  606.300484]   lock(&adev->gfx.kfd_sch_mutex);
[  606.300494]                                lock(&adev->enforce_isolation_mutex);
[  606.300508]                                lock(&adev->gfx.kfd_sch_mutex);
[  606.300521]   lock((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work));
[  606.300536]
                *** DEADLOCK ***

[  606.300546] 5 locks held by kworker/u96:3/3825:
[  606.300555]  #0: ffff9aa5aa1f5d58 ((wq_completion)comp_1.1.0){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  606.300577]  #1: ffffaa53c3c97e40 ((work_completion)(&sched->work_run_job)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  606.300600]  #2: ffff9aa64e463c98 (&adev->enforce_isolation_mutex){+.+.}-{3:3}, at: amdgpu_gfx_enforce_isolation_ring_begin_use+0x1c3/0x5d0 [amdgpu]
[  606.300837]  #3: ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.301062]  #4: ffffffff8c1a5660 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x70/0x610
[  606.301083]
               stack backtrace:
[  606.301092] CPU: 14 PID: 3825 Comm: kworker/u96:3 Tainted: G           OE      6.10.0-amd-mlkd-610-311224-lof torvalds#19
[  606.301109] Hardware name: Gigabyte Technology Co., Ltd. X570S GAMING X/X570S GAMING X, BIOS F7 03/22/2024
[  606.301124] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched]
[  606.301140] Call Trace:
[  606.301146]  <TASK>
[  606.301154]  dump_stack_lvl+0x9b/0xf0
[  606.301166]  dump_stack+0x10/0x20
[  606.301175]  print_circular_bug+0x26c/0x340
[  606.301187]  check_noncircular+0x157/0x170
[  606.301197]  ? register_lock_class+0x48/0x490
[  606.301213]  __lock_acquire+0x16f9/0x2810
[  606.301230]  lock_acquire+0xd1/0x300
[  606.301239]  ? __flush_work+0x232/0x610
[  606.301250]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301261]  ? mark_held_locks+0x54/0x90
[  606.301274]  ? __flush_work+0x232/0x610
[  606.301284]  __flush_work+0x250/0x610
[  606.301293]  ? __flush_work+0x232/0x610
[  606.301305]  ? __pfx_wq_barrier_func+0x10/0x10
[  606.301318]  ? mark_held_locks+0x54/0x90
[  606.301331]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301345]  cancel_delayed_work_sync+0x71/0x80
[  606.301356]  amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.301661]  amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.302050]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.302069]  amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.302452]  amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.302862]  ? drm_sched_entity_error+0x82/0x190 [gpu_sched]
[  606.302890]  amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.303366]  drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.303388]  process_one_work+0x21e/0x680
[  606.303409]  worker_thread+0x190/0x350
[  606.303424]  ? __pfx_worker_thread+0x10/0x10
[  606.303437]  kthread+0xe7/0x120
[  606.303449]  ? __pfx_kthread+0x10/0x10
[  606.303463]  ret_from_fork+0x3c/0x60
[  606.303476]  ? __pfx_kthread+0x10/0x10
[  606.303489]  ret_from_fork_asm+0x1a/0x30
[  606.303512]  </TASK>

v2: Refactor lock handling to resolve circular dependency (Alex)

- Introduced a `sched_work` flag to defer the call to
  `amdgpu_gfx_kfd_sch_ctrl` until after releasing
  `enforce_isolation_mutex`.
- This change ensures that `amdgpu_gfx_kfd_sch_ctrl` is called outside
  the critical section, preventing the circular dependency and deadlock.
- The `sched_work` flag is set within the mutex-protected section if
  conditions are met, and the actual function call is made afterward.
- This approach ensures consistent lock acquisition order.

Fixes: afefd6f ("drm/amdgpu: Implement Enforce Isolation Handler for KGD/KFD serialization")
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 0b6b2dd)
Cc: [email protected]
l1k pushed a commit that referenced this pull request Jan 23, 2025
syz reports an out of bounds read:

==================================================================
BUG: KASAN: slab-out-of-bounds in ocfs2_match fs/ocfs2/dir.c:334
[inline]
BUG: KASAN: slab-out-of-bounds in ocfs2_search_dirblock+0x283/0x6e0
fs/ocfs2/dir.c:367
Read of size 1 at addr ffff88804d8b9982 by task syz-executor.2/14802

CPU: 0 UID: 0 PID: 14802 Comm: syz-executor.2 Not tainted 6.13.0-rc4 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1
04/01/2014
Sched_ext: serialise (enabled+all), task: runnable_at=-10ms
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x229/0x350 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x164/0x530 mm/kasan/report.c:489
kasan_report+0x147/0x180 mm/kasan/report.c:602
ocfs2_match fs/ocfs2/dir.c:334 [inline]
ocfs2_search_dirblock+0x283/0x6e0 fs/ocfs2/dir.c:367
ocfs2_find_entry_id fs/ocfs2/dir.c:414 [inline]
ocfs2_find_entry+0x1143/0x2db0 fs/ocfs2/dir.c:1078
ocfs2_find_files_on_disk+0x18e/0x530 fs/ocfs2/dir.c:1981
ocfs2_lookup_ino_from_name+0xb6/0x110 fs/ocfs2/dir.c:2003
ocfs2_lookup+0x30a/0xd40 fs/ocfs2/namei.c:122
lookup_open fs/namei.c:3627 [inline]
open_last_lookups fs/namei.c:3748 [inline]
path_openat+0x145a/0x3870 fs/namei.c:3984
do_filp_open+0xe9/0x1c0 fs/namei.c:4014
do_sys_openat2+0x135/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x15d/0x1c0 fs/open.c:1428
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f01076903ad
Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f01084acfc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f01077cbf80 RCX: 00007f01076903ad
RDX: 0000000000105042 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f01077cbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f01077cbf80 R14: 00007f010764fc90 R15: 00007f010848d000
</TASK>
==================================================================

And a general protection fault in ocfs2_prepare_dir_for_insert:

==================================================================
loop0: detected capacity change from 0 to 32768
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data
mode.
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 5096 Comm: syz-executor792 Not tainted
6.11.0-rc4-syzkaller-00002-gb0da640826ba #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ocfs2_find_dir_space_id fs/ocfs2/dir.c:3406 [inline]
RIP: 0010:ocfs2_prepare_dir_for_insert+0x3309/0x5c70 fs/ocfs2/dir.c:4280
Code: 00 00 e8 2a 25 13 fe e9 ba 06 00 00 e8 20 25 13 fe e9 4f 01 00 00
e8 16 25 13 fe 49 8d 7f 08 49 8d 5f 09 48 89 f8 48 c1 e8 03 <42> 0f b6
04 20 84 c0 0f 85 bd 23 00 00 48 89 d8 48 c1 e8 03 42 0f
RSP: 0018:ffffc9000af9f020 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000009 RCX: ffff88801e27a440
RDX: 0000000000000000 RSI: 0000000000000400 RDI: 0000000000000008
RBP: ffffc9000af9f830 R08: ffffffff8380395b R09: ffffffff838090a7
R10: 0000000000000002 R11: ffff88801e27a440 R12: dffffc0000000000
R13: ffff88803c660878 R14: f700000000000088 R15: 0000000000000000
FS:  000055555a677380(0000) GS:ffff888020800000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560bce569178 CR3: 000000001de5a000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
vfs_mknod+0x36d/0x3b0 fs/namei.c:4088
do_mknodat+0x3ec/0x5b0
__do_sys_mknodat fs/namei.c:4166 [inline]
__se_sys_mknodat fs/namei.c:4163 [inline]
__x64_sys_mknodat+0xa7/0xc0 fs/namei.c:4163
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2dafda3a99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89
f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08
0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8
64 89 01 48
RSP: 002b:00007ffe336a6658 EFLAGS: 00000246 ORIG_RAX:
0000000000000103
RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
00007f2dafda3a99
RDX: 00000000000021c0 RSI: 0000000020000040 RDI:
00000000ffffff9c
RBP: 00007f2dafe1b5f0 R08: 0000000000004480 R09:
000055555a6784c0
R10: 0000000000000103 R11: 0000000000000246 R12:
00007ffe336a6680
R13: 00007ffe336a68a8 R14: 431bde82d7b634db R15:
00007f2dafdec03b
</TASK>
==================================================================

The two reports are all caused invalid negative i_size of dir inode.  For
ocfs2, dir_inode can't be negative or zero.

Here add a check in which is called by ocfs2_check_dir_for_entry().  It
fixes the second report as ocfs2_check_dir_for_entry() must be called
before ocfs2_prepare_dir_for_insert().  Also set a up limit for dir with
OCFS2_INLINE_DATA_FL.  The i_size can't be great than blocksize.

Link: https://lkml.kernel.org/r/[email protected]
Reported-by: Jiacheng Xu <[email protected]>
Link: https://lore.kernel.org/ocfs2-devel/[email protected]/T/#u
Reported-by: [email protected]
Link: https://lore.kernel.org/all/[email protected]/T/
Signed-off-by: Su Yue <[email protected]>
Reviewed-by: Heming Zhao <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Jun Piao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
Fix a lockdep warning [1] observed during the write combining test.

The warning indicates a potential nested lock scenario that could lead
to a deadlock.

However, this is a false positive alarm because the SF lock and its
parent lock are distinct ones.

The lockdep confusion arises because the locks belong to the same object
class (i.e., struct mlx5_core_dev).

To resolve this, the code has been refactored to avoid taking both
locks. Instead, only the parent lock is acquired.

[1]
raw_ethernet_bw/2118 is trying to acquire lock:
[  213.619032] ffff88811dd75e08 (&dev->wc_state_lock){+.+.}-{3:3}, at:
               mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.620270]
[  213.620270] but task is already holding lock:
[  213.620943] ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3}, at:
               mlx5_wc_support_get+0x10c/0x210 [mlx5_core]
[  213.622045]
[  213.622045] other info that might help us debug this:
[  213.622778]  Possible unsafe locking scenario:
[  213.622778]
[  213.623465]        CPU0
[  213.623815]        ----
[  213.624148]   lock(&dev->wc_state_lock);
[  213.624615]   lock(&dev->wc_state_lock);
[  213.625071]
[  213.625071]  *** DEADLOCK ***
[  213.625071]
[  213.625805]  May be due to missing lock nesting notation
[  213.625805]
[  213.626522] 4 locks held by raw_ethernet_bw/2118:
[  213.627019]  #0: ffff88813f80d578 (&uverbs_dev->disassociate_srcu){.+.+}-{0:0},
                at: ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.628088]  #1: ffff88810fb23930 (&file->hw_destroy_rwsem){.+.+}-{3:3},
                at: ib_init_ucontext+0x2d/0xf0 [ib_uverbs]
[  213.629094]  #2: ffff88810fb23878 (&file->ucontext_lock){+.+.}-{3:3},
                at: ib_init_ucontext+0x49/0xf0 [ib_uverbs]
[  213.630106]  #3: ffff88810b585e08 (&dev->wc_state_lock){+.+.}-{3:3},
                at: mlx5_wc_support_get+0x10c/0x210 [mlx5_core]
[  213.631185]
[  213.631185] stack backtrace:
[  213.631718] CPU: 1 UID: 0 PID: 2118 Comm: raw_ethernet_bw Not tainted
               6.12.0-rc7_internal_net_next_mlx5_89a0ad0 #1
[  213.632722] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
               rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[  213.633785] Call Trace:
[  213.634099]
[  213.634393]  dump_stack_lvl+0x7e/0xc0
[  213.634806]  print_deadlock_bug+0x278/0x3c0
[  213.635265]  __lock_acquire+0x15f4/0x2c40
[  213.635712]  lock_acquire+0xcd/0x2d0
[  213.636120]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.636722]  ? mlx5_ib_enable_lb+0x24/0xa0 [mlx5_ib]
[  213.637277]  __mutex_lock+0x81/0xda0
[  213.637697]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.638305]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.638902]  ? rcu_read_lock_sched_held+0x3f/0x70
[  213.639400]  ? mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.640016]  mlx5_wc_support_get+0x18c/0x210 [mlx5_core]
[  213.640615]  set_ucontext_resp+0x68/0x2b0 [mlx5_ib]
[  213.641144]  ? debug_mutex_init+0x33/0x40
[  213.641586]  mlx5_ib_alloc_ucontext+0x18e/0x7b0 [mlx5_ib]
[  213.642145]  ib_init_ucontext+0xa0/0xf0 [ib_uverbs]
[  213.642679]  ib_uverbs_handler_UVERBS_METHOD_GET_CONTEXT+0x95/0xc0
                [ib_uverbs]
[  213.643426]  ? _copy_from_user+0x46/0x80
[  213.643878]  ib_uverbs_cmd_verbs+0xa6b/0xc80 [ib_uverbs]
[  213.644426]  ? ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x130/0x130
               [ib_uverbs]
[  213.645213]  ? __lock_acquire+0xa99/0x2c40
[  213.645675]  ? lock_acquire+0xcd/0x2d0
[  213.646101]  ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.646625]  ? reacquire_held_locks+0xcf/0x1f0
[  213.647102]  ? do_user_addr_fault+0x45d/0x770
[  213.647586]  ib_uverbs_ioctl+0xe0/0x170 [ib_uverbs]
[  213.648102]  ? ib_uverbs_ioctl+0xc4/0x170 [ib_uverbs]
[  213.648632]  __x64_sys_ioctl+0x4d3/0xaa0
[  213.649060]  ? do_user_addr_fault+0x4a8/0x770
[  213.649528]  do_syscall_64+0x6d/0x140
[  213.649947]  entry_SYSCALL_64_after_hwframe+0x4b/0x53
[  213.650478] RIP: 0033:0x7fa179b0737b
[  213.650893] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c
               89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8
               10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d
               7d 2a 0f 00 f7 d8 64 89 01 48
[  213.652619] RSP: 002b:00007ffd2e6d46e8 EFLAGS: 00000246 ORIG_RAX:
               0000000000000010
[  213.653390] RAX: ffffffffffffffda RBX: 00007ffd2e6d47f8 RCX:
               00007fa179b0737b
[  213.654084] RDX: 00007ffd2e6d47e0 RSI: 00000000c0181b01 RDI:
               0000000000000003
[  213.654767] RBP: 00007ffd2e6d47c0 R08: 00007fa1799be010 R09:
               0000000000000002
[  213.655453] R10: 00007ffd2e6d4960 R11: 0000000000000246 R12:
               00007ffd2e6d487c
[  213.656170] R13: 0000000000000027 R14: 0000000000000001 R15:
               00007ffd2e6d4f70

Fixes: d98995b ("net/mlx5: Reimplement write combining test")
Signed-off-by: Yishai Hadas <[email protected]>
Reviewed-by: Michael Guralnik <[email protected]>
Reviewed-by: Larysa Zaremba <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Jan 23, 2025
Clear the port select structure on error so no stale values left after
definers are destroyed. That's because the mlx5_lag_destroy_definers()
always try to destroy all lag definers in the tt_map, so in the flow
below lag definers get double-destroyed and cause kernel crash:

  mlx5_lag_port_sel_create()
    mlx5_lag_create_definers()
      mlx5_lag_create_definer()     <- Failed on tt 1
        mlx5_lag_destroy_definers() <- definers[tt=0] gets destroyed
  mlx5_lag_port_sel_create()
    mlx5_lag_create_definers()
      mlx5_lag_create_definer()     <- Failed on tt 0
        mlx5_lag_destroy_definers() <- definers[tt=0] gets double-destroyed

 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
 Mem abort info:
   ESR = 0x0000000096000005
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x05: level 1 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 64k pages, 48-bit VAs, pgdp=0000000112ce2e00
 [0000000000000008] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
 Modules linked in: iptable_raw bonding ip_gre ip6_gre gre ip6_tunnel tunnel6 geneve ip6_udp_tunnel udp_tunnel ipip tunnel4 ip_tunnel rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) ib_uverbs(OE) mlx5_fwctl(OE) fwctl(OE) mlx5_core(OE) mlxdevm(OE) ib_core(OE) mlxfw(OE) memtrack(OE) mlx_compat(OE) openvswitch nsh nf_conncount psample xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo xt_addrtype iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc netconsole overlay efi_pstore sch_fq_codel zram ip_tables crct10dif_ce qemu_fw_cfg fuse ipv6 crc_ccitt [last unloaded: mlx_compat(OE)]
  CPU: 3 UID: 0 PID: 217 Comm: kworker/u53:2 Tainted: G           OE      6.11.0+ #2
  Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
  Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
  Workqueue: mlx5_lag mlx5_do_bond_work [mlx5_core]
  pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core]
  lr : mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core]
  sp : ffff800085fafb00
  x29: ffff800085fafb00 x28: ffff0000da0c8000 x27: 0000000000000000
  x26: ffff0000da0c8000 x25: ffff0000da0c8000 x24: ffff0000da0c8000
  x23: ffff0000c31f81a0 x22: 0400000000000000 x21: ffff0000da0c8000
  x20: 0000000000000000 x19: 0000000000000001 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffff8b0c9350
  x14: 0000000000000000 x13: ffff800081390d18 x12: ffff800081dc3cc0
  x11: 0000000000000001 x10: 0000000000000b10 x9 : ffff80007ab7304c
  x8 : ffff0000d00711f0 x7 : 0000000000000004 x6 : 0000000000000190
  x5 : ffff00027edb3010 x4 : 0000000000000000 x3 : 0000000000000000
  x2 : ffff0000d39b8000 x1 : ffff0000d39b8000 x0 : 0400000000000000
  Call trace:
   mlx5_del_flow_rules+0x24/0x2c0 [mlx5_core]
   mlx5_lag_destroy_definer+0x54/0x100 [mlx5_core]
   mlx5_lag_destroy_definers+0xa0/0x108 [mlx5_core]
   mlx5_lag_port_sel_create+0x2d4/0x6f8 [mlx5_core]
   mlx5_activate_lag+0x60c/0x6f8 [mlx5_core]
   mlx5_do_bond_work+0x284/0x5c8 [mlx5_core]
   process_one_work+0x170/0x3e0
   worker_thread+0x2d8/0x3e0
   kthread+0x11c/0x128
   ret_from_fork+0x10/0x20
  Code: a9025bf5 aa0003f6 a90363f7 f90023f9 (f9400400)
  ---[ end trace 0000000000000000 ]---

Fixes: dc48516 ("net/mlx5: Lag, add support to create definers for LAG")
Signed-off-by: Mark Zhang <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Reviewed-by: Mark Bloch <[email protected]>
Reviewed-by: Jacob Keller <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Feb 2, 2025
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 torvalds#7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 torvalds#8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 torvalds#9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Feb 3, 2025
In "one-shot" mode, turbostat
1. takes a counter snapshot
2. forks and waits for a child
3. takes the end counter snapshot and prints the result.

But turbostat counter snapshots currently use affinity to travel
around the system so that counter reads are "local", and this
affinity must be cleared between #1 and #2 above.

The offending commit removed that reset that allowed the child
to run on cpu_present_set.

Fix that issue, and improve upon the original by using
cpu_possible_set for the child.  This allows the child
to also run on CPUs that hotplug online during its runtime.

Reported-by: Zhang Rui <[email protected]>
Fixes: 7bb3fe2 ("tools/power/turbostat: Obey allowed CPUs during startup")
Signed-off-by: Len Brown <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 10, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> l1k#2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> l1k#1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    l1k#1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    l1k#2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    l1k#3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    l1k#4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    l1k#5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    l1k#6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    torvalds#7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
Since commit 6037802 ("power: supply: core: implement extension API")
there is the following ABBA deadlock (simplified) between the LED trigger
code and the power-supply code:

1) When registering a power-supply class device, power_supply_register()
calls led_trigger_register() from power_supply_create_triggers() in
a scoped_guard(rwsem_read, &psy->extensions_sem) context.
led_trigger_register() then in turn takes a LED subsystem lock.
So here we have the following locking order:

* Read-lock extensions_sem
* Lock LED subsystem lock(s)

2) When registering a LED class device, with its default trigger set
to a power-supply LED trigger (which has already been registered)
The LED class code calls power_supply_led_trigger_activate() when
setting up the default trigger. power_supply_led_trigger_activate()
calls power_supply_get_property() to determine the initial value of
to assign to the LED and that read-locks extensions_sem. So now we
have the following locking order:

* Lock LED subsystem lock(s)
* Read-lock extensions_sem

Fixing this is easy, there is no need to hold the extensions_sem when
calling power_supply_create_triggers() since all triggers are always
created rather then checking for the presence of certain attributes as
power_supply_add_hwmon_sysfs() does. Move power_supply_create_triggers()
out of the guard block to fix this.

Here is the lockdep report fixed by this change:

[   31.249343] ======================================================
[   31.249378] WARNING: possible circular locking dependency detected
[   31.249413] 6.13.0-rc6+ torvalds#251 Tainted: G         C  E
[   31.249440] ------------------------------------------------------
[   31.249471] (udev-worker)/553 is trying to acquire lock:
[   31.249501] ffff892adbcaf660 (&psy->extensions_sem){.+.+}-{4:4}, at: power_supply_get_property.part.0+0x22/0x150
[   31.249574]
               but task is already holding lock:
[   31.249603] ffff892adbc0bad0 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x34/0xe0
[   31.249657]
               which lock already depends on the new lock.

[   31.249696]
               the existing dependency chain (in reverse order) is:
[   31.249735]
               -> l1k#2 (&led_cdev->trigger_lock){+.+.}-{4:4}:
[   31.249778]        down_write+0x3b/0xd0
[   31.249803]        led_trigger_set_default+0x34/0xe0
[   31.249833]        led_classdev_register_ext+0x311/0x3a0
[   31.249863]        input_leds_connect+0x1dc/0x2a0
[   31.249889]        input_attach_handler.isra.0+0x75/0x90
[   31.249921]        input_register_device.cold+0xa1/0x150
[   31.249955]        hidinput_connect+0x8a2/0xb80
[   31.249982]        hid_connect+0x582/0x5c0
[   31.250007]        hid_hw_start+0x3f/0x60
[   31.250030]        hid_device_probe+0x122/0x1f0
[   31.250053]        really_probe+0xde/0x340
[   31.250080]        __driver_probe_device+0x78/0x110
[   31.250105]        driver_probe_device+0x1f/0xa0
[   31.250132]        __device_attach_driver+0x85/0x110
[   31.250160]        bus_for_each_drv+0x78/0xc0
[   31.250184]        __device_attach+0xb0/0x1b0
[   31.250207]        bus_probe_device+0x94/0xb0
[   31.250230]        device_add+0x64a/0x860
[   31.250252]        hid_add_device+0xe5/0x240
[   31.250279]        usbhid_probe+0x4dc/0x620
[   31.250303]        usb_probe_interface+0xe4/0x2a0
[   31.250329]        really_probe+0xde/0x340
[   31.250353]        __driver_probe_device+0x78/0x110
[   31.250377]        driver_probe_device+0x1f/0xa0
[   31.250404]        __device_attach_driver+0x85/0x110
[   31.250431]        bus_for_each_drv+0x78/0xc0
[   31.250455]        __device_attach+0xb0/0x1b0
[   31.250478]        bus_probe_device+0x94/0xb0
[   31.250501]        device_add+0x64a/0x860
[   31.250523]        usb_set_configuration+0x606/0x8a0
[   31.250552]        usb_generic_driver_probe+0x3e/0x60
[   31.250579]        usb_probe_device+0x3d/0x120
[   31.250605]        really_probe+0xde/0x340
[   31.250629]        __driver_probe_device+0x78/0x110
[   31.250653]        driver_probe_device+0x1f/0xa0
[   31.250680]        __device_attach_driver+0x85/0x110
[   31.250707]        bus_for_each_drv+0x78/0xc0
[   31.250731]        __device_attach+0xb0/0x1b0
[   31.250753]        bus_probe_device+0x94/0xb0
[   31.250776]        device_add+0x64a/0x860
[   31.250798]        usb_new_device.cold+0x141/0x38f
[   31.250828]        hub_event+0x1166/0x1980
[   31.250854]        process_one_work+0x20f/0x580
[   31.250879]        worker_thread+0x1d1/0x3b0
[   31.250904]        kthread+0xee/0x120
[   31.250926]        ret_from_fork+0x30/0x50
[   31.250954]        ret_from_fork_asm+0x1a/0x30
[   31.250982]
               -> l1k#1 (triggers_list_lock){++++}-{4:4}:
[   31.251022]        down_write+0x3b/0xd0
[   31.251045]        led_trigger_register+0x40/0x1b0
[   31.251074]        power_supply_register_led_trigger+0x88/0x150
[   31.251107]        power_supply_create_triggers+0x55/0xe0
[   31.251135]        __power_supply_register.part.0+0x34e/0x4a0
[   31.251164]        devm_power_supply_register+0x70/0xc0
[   31.251190]        bq27xxx_battery_setup+0x1a1/0x6d0 [bq27xxx_battery]
[   31.251235]        bq27xxx_battery_i2c_probe+0xe5/0x17f [bq27xxx_battery_i2c]
[   31.251272]        i2c_device_probe+0x125/0x2b0
[   31.251299]        really_probe+0xde/0x340
[   31.251324]        __driver_probe_device+0x78/0x110
[   31.251348]        driver_probe_device+0x1f/0xa0
[   31.251375]        __driver_attach+0xba/0x1c0
[   31.251398]        bus_for_each_dev+0x6b/0xb0
[   31.251421]        bus_add_driver+0x111/0x1f0
[   31.251445]        driver_register+0x6e/0xc0
[   31.251470]        i2c_register_driver+0x41/0xb0
[   31.251498]        do_one_initcall+0x5e/0x3a0
[   31.251522]        do_init_module+0x60/0x220
[   31.251550]        __do_sys_init_module+0x15f/0x190
[   31.251575]        do_syscall_64+0x93/0x180
[   31.251598]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   31.251629]
               -> #0 (&psy->extensions_sem){.+.+}-{4:4}:
[   31.251668]        __lock_acquire+0x13ce/0x21c0
[   31.251694]        lock_acquire+0xcf/0x2e0
[   31.251719]        down_read+0x3e/0x170
[   31.251741]        power_supply_get_property.part.0+0x22/0x150
[   31.251774]        power_supply_update_leds+0x8d/0x230
[   31.251804]        power_supply_led_trigger_activate+0x18/0x20
[   31.251837]        led_trigger_set+0x1fc/0x300
[   31.251863]        led_trigger_set_default+0x90/0xe0
[   31.251892]        led_classdev_register_ext+0x311/0x3a0
[   31.251921]        devm_led_classdev_multicolor_register_ext+0x6e/0xb80 [led_class_multicolor]
[   31.251969]        ktd202x_probe+0x464/0x5c0 [leds_ktd202x]
[   31.252002]        i2c_device_probe+0x125/0x2b0
[   31.252027]        really_probe+0xde/0x340
[   31.252052]        __driver_probe_device+0x78/0x110
[   31.252076]        driver_probe_device+0x1f/0xa0
[   31.252103]        __driver_attach+0xba/0x1c0
[   31.252125]        bus_for_each_dev+0x6b/0xb0
[   31.252148]        bus_add_driver+0x111/0x1f0
[   31.252172]        driver_register+0x6e/0xc0
[   31.252197]        i2c_register_driver+0x41/0xb0
[   31.252225]        do_one_initcall+0x5e/0x3a0
[   31.252248]        do_init_module+0x60/0x220
[   31.252274]        __do_sys_init_module+0x15f/0x190
[   31.253986]        do_syscall_64+0x93/0x180
[   31.255826]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   31.257614]
               other info that might help us debug this:

[   31.257619] Chain exists of:
                 &psy->extensions_sem --> triggers_list_lock --> &led_cdev->trigger_lock

[   31.257630]  Possible unsafe locking scenario:

[   31.257632]        CPU0                    CPU1
[   31.257633]        ----                    ----
[   31.257634]   lock(&led_cdev->trigger_lock);
[   31.257637]                                lock(triggers_list_lock);
[   31.257640]                                lock(&led_cdev->trigger_lock);
[   31.257643]   rlock(&psy->extensions_sem);
[   31.257646]
                *** DEADLOCK ***

[   31.289433] 4 locks held by (udev-worker)/553:
[   31.289443]  #0: ffff892ad9658108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xaf/0x1c0
[   31.289463]  l1k#1: ffff892adbc0bbc8 (&led_cdev->led_access){+.+.}-{4:4}, at: led_classdev_register_ext+0x1c7/0x3a0
[   31.289476]  l1k#2: ffffffffad0e30b0 (triggers_list_lock){++++}-{4:4}, at: led_trigger_set_default+0x2c/0xe0
[   31.289487]  l1k#3: ffff892adbc0bad0 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x34/0xe0

Fixes: 6037802 ("power: supply: core: implement extension API")
Cc: Thomas Weißschuh <[email protected]>
Cc: Armin Wolf <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Reviewed-by: Thomas Weißschuh <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sebastian Reichel <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
…ea as VM_ALLOC

Erhard reported the following KASAN hit while booting his PowerMac G4
with a KASAN-enabled kernel 6.13-rc6:

  BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8
  Write of size 8 at addr f1000000 by task chronyd/1293

  CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G        W          6.13.0-rc6-PMacG4 l1k#2
  Tainted: [W]=WARN
  Hardware name: PowerMac3,6 7455 0x80010303 PowerMac
  Call Trace:
  [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable)
  [c24375b0] [c0504998] print_report+0xdc/0x504
  [c2437610] [c050475c] kasan_report+0xf8/0x108
  [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c
  [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8
  [c24376c0] [c004c014] patch_instructions+0x15c/0x16c
  [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c
  [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac
  [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec
  [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478
  [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14
  [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4
  [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890
  [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420
  [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c
  --- interrupt: c00 at 0x5a1274
  NIP:  005a1274 LR: 006a3b3c CTR: 005296c8
  REGS: c2437f40 TRAP: 0c00   Tainted: G        W           (6.13.0-rc6-PMacG4)
  MSR:  0200f932 <VEC,EE,PR,FP,ME,IR,DR,RI>  CR: 24004422  XER: 00000000

  GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932
  GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57
  GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002
  GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001
  NIP [005a1274] 0x5a1274
  LR [006a3b3c] 0x6a3b3c
  --- interrupt: c00

  The buggy address belongs to the virtual mapping at
   [f1000000, f1002000) created by:
   text_area_cpu_up+0x20/0x190

  The buggy address belongs to the physical page:
  page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30
  flags: 0x80000000(zone=2)
  raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001
  raw: 00000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  >f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
             ^
   f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
   f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
  ==================================================================

f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not
initialised hence not supposed to be used yet.

Powerpc text patching infrastructure allocates a virtual memory area
using get_vm_area() and flags it as VM_ALLOC. But that flag is meant
to be used for vmalloc() and vmalloc() allocated memory is not
supposed to be used before a call to __vmalloc_node_range() which is
never called for that area.

That went undetected until commit e4137f0 ("mm, kasan, kmsan:
instrument copy_from/to_kernel_nofault")

The area allocated by text_area_cpu_up() is not vmalloc memory, it is
mapped directly on demand when needed by map_kernel_page(). There is
no VM flag corresponding to such usage, so just pass no flag. That way
the area will be unpoisonned and usable immediately.

Reported-by: Erhard Furtner <[email protected]>
Closes: https://lore.kernel.org/all/20250112135832.57c92322@yea/
Fixes: 37bc3e5 ("powerpc/lib/code-patching: Use alternate map for patch_instruction()")
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Madhavan Srinivasan <[email protected]>
Link: https://patch.msgid.link/06621423da339b374f48c0886e3a5db18e896be8.1739342693.git.christophe.leroy@csgroup.eu
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument l1k#4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument l1k#3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument l1k#2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument l1k#1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument torvalds#8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument torvalds#7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument l1k#6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument l1k#5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Feb 26, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.14, take l1k#2

- Large set of fixes for vector handling, specially in the interactions
  between host and guest state. This fixes a number of bugs affecting
  actual deployments, and greatly simplifies the FP/SIMD/SVE handling.
  Thanks to Mark Rutland for dealing with this thankless task.

- Fix an ugly race between vcpu and vgic creation/init, resulting in
  unexpected behaviours.

- Fix use of kernel VAs at EL2 when emulating timers with nVHE.

- Small set of pKVM improvements and cleanups.
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Mar 9, 2025
Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.

    [    4.239592] =============================
    [    4.239595] [ BUG: Invalid wait context ]
    [    4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35 Not tainted
    [    4.239603] -----------------------------
    [    4.239606] kworker/u8:5/76 is trying to lock:
    [    4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.239641] other info that might help us debug this:
    [    4.239643] context-{5:5}
    [    4.239646] 5 locks held by kworker/u8:5/76:
    [    4.239651]  #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
    [    4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.254094]  l1k#1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
    [    4.254109]  l1k#2: ffff00000920c8f8
    [    4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
    [    4.264803]  (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
    [    4.264820]  l1k#3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
    [    4.264840]  l1k#4:
    [    4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
    [    4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
    [    4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
    [    4.304082] stack backtrace:
    [    4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35
    [    4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
    [    4.304097] Workqueue: async async_run_entry_fn
    [    4.304106] Call trace:
    [    4.304110]  show_stack+0x14/0x20 (C)
    [    4.304122]  dump_stack_lvl+0x6c/0x90
    [    4.304131]  dump_stack+0x14/0x1c
    [    4.304138]  __lock_acquire+0xdfc/0x1584
    [    4.426274]  lock_acquire+0x1c4/0x33c
    [    4.429942]  _raw_spin_lock_irqsave+0x5c/0x80
    [    4.434307]  gpio_rcar_config_interrupt_input_mode+0x34/0x164
    [    4.440061]  gpio_rcar_irq_set_type+0xd4/0xd8
    [    4.444422]  __irq_set_trigger+0x5c/0x178
    [    4.448435]  __setup_irq+0x2e4/0x690
    [    4.452012]  request_threaded_irq+0xc4/0x190
    [    4.456285]  devm_request_threaded_irq+0x7c/0xf4
    [    4.459398] ata1: link resume succeeded after 1 retries
    [    4.460902]  mmc_gpiod_request_cd_irq+0x68/0xe0
    [    4.470660]  mmc_start_host+0x50/0xac
    [    4.474327]  mmc_add_host+0x80/0xe4
    [    4.477817]  tmio_mmc_host_probe+0x2b0/0x440
    [    4.482094]  renesas_sdhi_probe+0x488/0x6f4
    [    4.486281]  renesas_sdhi_internal_dmac_probe+0x60/0x78
    [    4.491509]  platform_probe+0x64/0xd8
    [    4.495178]  really_probe+0xb8/0x2a8
    [    4.498756]  __driver_probe_device+0x74/0x118
    [    4.503116]  driver_probe_device+0x3c/0x154
    [    4.507303]  __device_attach_driver+0xd4/0x160
    [    4.511750]  bus_for_each_drv+0x84/0xe0
    [    4.515588]  __device_attach_async_helper+0xb0/0xdc
    [    4.520470]  async_run_entry_fn+0x30/0xd8
    [    4.524481]  process_one_work+0x210/0x62c
    [    4.528494]  worker_thread+0x1ac/0x340
    [    4.532245]  kthread+0x10c/0x110
    [    4.535476]  ret_from_fork+0x10/0x20

Signed-off-by: Niklas Söderlund <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
l1k pushed a commit that referenced this pull request Mar 10, 2025
 into HEAD

KVM x86 fixes for 6.14-rcN #2

 - Set RFLAGS.IF in C code on SVM to get VMRUN out of the STI shadow.

 - Ensure DEBUGCTL is context switched on AMD to avoid running the guest with
   the host's value, which can lead to unexpected bus lock #DBs.

 - Suppress DEBUGCTL.BTF on AMD (to match Intel), as KVM doesn't properly
   emulate BTF.  KVM's lack of context switching has meant BTF has always been
   broken to some extent.

 - Always save DR masks for SNP vCPUs if DebugSwap is *supported*, as the guest
   can enable DebugSwap without KVM's knowledge.

 - Fix a bug in mmu_stress_tests where a vCPU could finish the "writes to RO
   memory" phase without actually generating a write-protection fault.

 - Fix a printf() goof in the SEV smoke test that causes build failures with
   -Werror.

 - Explicitly zero EAX and EBX in CPUID.0x8000_0022 output when PERFMON_V2
   isn't supported by KVM.
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Mar 24, 2025
…cal section

A circular lock dependency splat has been seen involving down_trylock():

  ======================================================
  WARNING: possible circular locking dependency detected
  6.12.0-41.el10.s390x+debug
  ------------------------------------------------------
  dd/32479 is trying to acquire lock:
  0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90

  but task is already holding lock:
  000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0

  the existing dependency chain (in reverse order) is:
  -> l1k#4 (&zone->lock){-.-.}-{2:2}:
  -> l1k#3 (hrtimer_bases.lock){-.-.}-{2:2}:
  -> l1k#2 (&rq->__lock){-.-.}-{2:2}:
  -> l1k#1 (&p->pi_lock){-.-.}-{2:2}:
  -> #0 ((console_sem).lock){-.-.}-{2:2}:

The console_sem -> pi_lock dependency is due to calling try_to_wake_up()
while holding the console_sem raw_spinlock. This dependency can be broken
by using wake_q to do the wakeup instead of calling try_to_wake_up()
under the console_sem lock. This will also make the semaphore's
raw_spinlock become a terminal lock without taking any further locks
underneath it.

The hrtimer_bases.lock is a raw_spinlock while zone->lock is a
spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via
the debug_objects_fill_pool() helper function in the debugobjects code.

  -> l1k#4 (&zone->lock){-.-.}-{2:2}:
         __lock_acquire+0xe86/0x1cc0
         lock_acquire.part.0+0x258/0x630
         lock_acquire+0xb8/0xe0
         _raw_spin_lock_irqsave+0xb4/0x120
         rmqueue_bulk+0xac/0x8f0
         __rmqueue_pcplist+0x580/0x830
         rmqueue_pcplist+0xfc/0x470
         rmqueue.isra.0+0xdec/0x11b0
         get_page_from_freelist+0x2ee/0xeb0
         __alloc_pages_noprof+0x2c2/0x520
         alloc_pages_mpol_noprof+0x1fc/0x4d0
         alloc_pages_noprof+0x8c/0xe0
         allocate_slab+0x320/0x460
         ___slab_alloc+0xa58/0x12b0
         __slab_alloc.isra.0+0x42/0x60
         kmem_cache_alloc_noprof+0x304/0x350
         fill_pool+0xf6/0x450
         debug_object_activate+0xfe/0x360
         enqueue_hrtimer+0x34/0x190
         __run_hrtimer+0x3c8/0x4c0
         __hrtimer_run_queues+0x1b2/0x260
         hrtimer_interrupt+0x316/0x760
         do_IRQ+0x9a/0xe0
         do_irq_async+0xf6/0x160

Normally a raw_spinlock to spinlock dependency is not legitimate
and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled,
but debug_objects_fill_pool() is an exception as it explicitly
allows this dependency for non-PREEMPT_RT kernel without causing
PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is
legitimate and not a bug.

Anyway, semaphore is the only locking primitive left that is still
using try_to_wake_up() to do wakeup inside critical section, all the
other locking primitives had been migrated to use wake_q to do wakeup
outside of the critical section. It is also possible that there are
other circular locking dependencies involving printk/console_sem or
other existing/new semaphores lurking somewhere which may show up in
the future. Let just do the migration now to wake_q to avoid headache
like this.

Reported-by: [email protected]
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Mar 24, 2025
A blocking notification chain uses a read-write semaphore to protect the
integrity of the chain. The semaphore is acquired for writing when
adding / removing notifiers to / from the chain and acquired for reading
when traversing the chain and informing notifiers about an event.

In case of the blocking switchdev notification chain, recursive
notifications are possible which leads to the semaphore being acquired
twice for reading and to lockdep warnings being generated [1].

Specifically, this can happen when the bridge driver processes a
SWITCHDEV_BRPORT_UNOFFLOADED event which causes it to emit notifications
about deferred events when calling switchdev_deferred_process().

Fix this by converting the notification chain to a raw notification
chain in a similar fashion to the netdev notification chain. Protect
the chain using the RTNL mutex by acquiring it when modifying the chain.
Events are always informed under the RTNL mutex, but add an assertion in
call_switchdev_blocking_notifiers() to make sure this is not violated in
the future.

Maintain the "blocking" prefix as events are always emitted from process
context and listeners are allowed to block.

[1]:
WARNING: possible recursive locking detected
6.14.0-rc4-custom-g079270089484 l1k#1 Not tainted
--------------------------------------------
ip/52731 is trying to acquire lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0

but task is already holding lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0

other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock((switchdev_blocking_notif_chain).rwsem);
lock((switchdev_blocking_notif_chain).rwsem);

*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by ip/52731:
 #0: ffffffff84f795b0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x727/0x1dc0
 l1k#1: ffffffff8731f628 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x790/0x1dc0
 l1k#2: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0

stack backtrace:
...
? __pfx_down_read+0x10/0x10
? __pfx_mark_lock+0x10/0x10
? __pfx_switchdev_port_attr_set_deferred+0x10/0x10
blocking_notifier_call_chain+0x58/0xa0
switchdev_port_attr_notify.constprop.0+0xb3/0x1b0
? __pfx_switchdev_port_attr_notify.constprop.0+0x10/0x10
? mark_held_locks+0x94/0xe0
? switchdev_deferred_process+0x11a/0x340
switchdev_port_attr_set_deferred+0x27/0xd0
switchdev_deferred_process+0x164/0x340
br_switchdev_port_unoffload+0xc8/0x100 [bridge]
br_switchdev_blocking_event+0x29f/0x580 [bridge]
notifier_call_chain+0xa2/0x440
blocking_notifier_call_chain+0x6e/0xa0
switchdev_bridge_port_unoffload+0xde/0x1a0
...

Fixes: f7a70d6 ("net: bridge: switchdev: Ensure deferred event delivery on unoffload")
Signed-off-by: Amit Cohen <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Vladimir Oltean <[email protected]>
Tested-by: Vladimir Oltean <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Mar 24, 2025
When on a MANA VM hibernation is triggered, as part of hibernate_snapshot(),
mana_gd_suspend() and mana_gd_resume() are called. If during this
mana_gd_resume(), a failure occurs with HWC creation, mana_port_debugfs
pointer does not get reinitialized and ends up pointing to older,
cleaned-up dentry.
Further in the hibernation path, as part of power_down(), mana_gd_shutdown()
is triggered. This call, unaware of the failures in resume, tries to cleanup
the already cleaned up  mana_port_debugfs value and hits the following bug:

[  191.359296] mana 7870:00:00.0: Shutdown was called
[  191.359918] BUG: kernel NULL pointer dereference, address: 0000000000000098
[  191.360584] #PF: supervisor write access in kernel mode
[  191.361125] #PF: error_code(0x0002) - not-present page
[  191.361727] PGD 1080ea067 P4D 0
[  191.362172] Oops: Oops: 0002 [l1k#1] SMP NOPTI
[  191.362606] CPU: 11 UID: 0 PID: 1674 Comm: bash Not tainted 6.14.0-rc5+ l1k#2
[  191.363292] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024
[  191.364124] RIP: 0010:down_write+0x19/0x50
[  191.364537] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb e8 de cd ff ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 13 75 16 65 48 8b 05 88 24 4c 6a 48 89 43 08 48 8b 5d
[  191.365867] RSP: 0000:ff45fbe0c1c037b8 EFLAGS: 00010246
[  191.366350] RAX: 0000000000000000 RBX: 0000000000000098 RCX: ffffff8100000000
[  191.366951] RDX: 0000000000000001 RSI: 0000000000000064 RDI: 0000000000000098
[  191.367600] RBP: ff45fbe0c1c037c0 R08: 0000000000000000 R09: 0000000000000001
[  191.368225] R10: ff45fbe0d2b01000 R11: 0000000000000008 R12: 0000000000000000
[  191.368874] R13: 000000000000000b R14: ff43dc27509d67c0 R15: 0000000000000020
[  191.369549] FS:  00007dbc5001e740(0000) GS:ff43dc663f380000(0000) knlGS:0000000000000000
[  191.370213] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  191.370830] CR2: 0000000000000098 CR3: 0000000168e8e002 CR4: 0000000000b73ef0
[  191.371557] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  191.372192] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[  191.372906] Call Trace:
[  191.373262]  <TASK>
[  191.373621]  ? show_regs+0x64/0x70
[  191.374040]  ? __die+0x24/0x70
[  191.374468]  ? page_fault_oops+0x290/0x5b0
[  191.374875]  ? do_user_addr_fault+0x448/0x800
[  191.375357]  ? exc_page_fault+0x7a/0x160
[  191.375971]  ? asm_exc_page_fault+0x27/0x30
[  191.376416]  ? down_write+0x19/0x50
[  191.376832]  ? down_write+0x12/0x50
[  191.377232]  simple_recursive_removal+0x4a/0x2a0
[  191.377679]  ? __pfx_remove_one+0x10/0x10
[  191.378088]  debugfs_remove+0x44/0x70
[  191.378530]  mana_detach+0x17c/0x4f0
[  191.378950]  ? __flush_work+0x1e2/0x3b0
[  191.379362]  ? __cond_resched+0x1a/0x50
[  191.379787]  mana_remove+0xf2/0x1a0
[  191.380193]  mana_gd_shutdown+0x3b/0x70
[  191.380642]  pci_device_shutdown+0x3a/0x80
[  191.381063]  device_shutdown+0x13e/0x230
[  191.381480]  kernel_power_off+0x35/0x80
[  191.381890]  hibernate+0x3c6/0x470
[  191.382312]  state_store+0xcb/0xd0
[  191.382734]  kobj_attr_store+0x12/0x30
[  191.383211]  sysfs_kf_write+0x3e/0x50
[  191.383640]  kernfs_fop_write_iter+0x140/0x1d0
[  191.384106]  vfs_write+0x271/0x440
[  191.384521]  ksys_write+0x72/0xf0
[  191.384924]  __x64_sys_write+0x19/0x20
[  191.385313]  x64_sys_call+0x2b0/0x20b0
[  191.385736]  do_syscall_64+0x79/0x150
[  191.386146]  ? __mod_memcg_lruvec_state+0xe7/0x240
[  191.386676]  ? __lruvec_stat_mod_folio+0x79/0xb0
[  191.387124]  ? __pfx_lru_add+0x10/0x10
[  191.387515]  ? queued_spin_unlock+0x9/0x10
[  191.387937]  ? do_anonymous_page+0x33c/0xa00
[  191.388374]  ? __handle_mm_fault+0xcf3/0x1210
[  191.388805]  ? __count_memcg_events+0xbe/0x180
[  191.389235]  ? handle_mm_fault+0xae/0x300
[  191.389588]  ? do_user_addr_fault+0x559/0x800
[  191.390027]  ? irqentry_exit_to_user_mode+0x43/0x230
[  191.390525]  ? irqentry_exit+0x1d/0x30
[  191.390879]  ? exc_page_fault+0x86/0x160
[  191.391235]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  191.391745] RIP: 0033:0x7dbc4ff1c574
[  191.392111] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
[  191.393412] RSP: 002b:00007ffd95a23ab8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  191.393990] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007dbc4ff1c574
[  191.394594] RDX: 0000000000000005 RSI: 00005a6eeadb0ce0 RDI: 0000000000000001
[  191.395215] RBP: 00007ffd95a23ae0 R08: 00007dbc50003b20 R09: 0000000000000000
[  191.395805] R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000000005
[  191.396404] R13: 00005a6eeadb0ce0 R14: 00007dbc500045c0 R15: 00007dbc50001ee0
[  191.396987]  </TASK>

To fix this, we explicitly set such mana debugfs variables to NULL after
debugfs_remove() is called.

Fixes: 6607c17 ("net: mana: Enable debugfs files for MANA device")
Cc: [email protected]
Signed-off-by: Shradha Gupta <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Link: https://patch.msgid.link/1741688260-28922-1-git-send-email-shradhagupta@linux.microsoft.com
Signed-off-by: Paolo Abeni <[email protected]>
l1k pushed a commit that referenced this pull request Apr 3, 2025
When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
which causes the flush_bio to be throttled by wbt_wait().

An example from v5.4, similar problem also exists in upstream:

    crash> bt 2091206
    PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
     #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
     #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
     #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
     #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
     #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
     #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
     #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
     torvalds#7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
     torvalds#8 [ffff800084a2fa60] generic_make_request at ffff800040570138
     torvalds#9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
    torvalds#10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
    torvalds#11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
    torvalds#12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
    torvalds#13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
    torvalds#14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
    torvalds#15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
    torvalds#16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
    torvalds#17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
    torvalds#18 [ffff800084a2fe70] kthread at ffff800040118de4

After commit 2def284 ("xfs: don't allow log IO to be throttled"),
the metadata submitted by xlog_write_iclog() should not be throttled.
But due to the existence of the dm layer, throttling flush_bio indirectly
causes the metadata bio to be throttled.

Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
wbt_should_throttle() return false to avoid wbt_wait().

Signed-off-by: Jinliang Zheng <[email protected]>
Reviewed-by: Tianxiang Peng <[email protected]>
Reviewed-by: Hao Peng <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
l1k pushed a commit that referenced this pull request Apr 4, 2025
Currently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding
the per-CPU acomp_ctx mutex.  crypto_free_acomp() then holds scomp_lock
(through crypto_exit_scomp_ops_async()).

On the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through
crypto_scomp_init_tfm()), and then allocates memory.  If the allocation
results in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex.

The above dependencies can cause an ABBA deadlock.  For example in the
following scenario:

(1) Task A running on CPU #1:
    crypto_alloc_acomp_node()
      Holds scomp_lock
      Enters reclaim
      Reads per_cpu_ptr(pool->acomp_ctx, 1)

(2) Task A is descheduled

(3) CPU #1 goes offline
    zswap_cpu_comp_dead(CPU #1)
      Holds per_cpu_ptr(pool->acomp_ctx, 1))
      Calls crypto_free_acomp()
      Waits for scomp_lock

(4) Task A running on CPU #2:
      Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1
      DEADLOCK

Since there is no requirement to call crypto_free_acomp() with the per-CPU
acomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is
unlocked.  Also move the acomp_request_free() and kfree() calls for
consistency and to avoid any potential sublte locking dependencies in the
future.

With this, only setting acomp_ctx fields to NULL occurs with the mutex
held.  This is similar to how zswap_cpu_comp_prepare() only initializes
acomp_ctx fields with the mutex held, after performing all allocations
before holding the mutex.

Opportunistically, move the NULL check on acomp_ctx so that it takes place
before the mutex dereference.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 12dcb0e ("mm: zswap: properly synchronize freeing resources during CPU hotunplug")
Signed-off-by: Herbert Xu <[email protected]>
Co-developed-by: Herbert Xu <[email protected]>
Signed-off-by: Yosry Ahmed <[email protected]>
Reported-by: [email protected]
Closes: https://lore.kernel.org/all/[email protected]/
Acked-by: Herbert Xu <[email protected]>
Reviewed-by: Chengming Zhou <[email protected]>
Reviewed-by: Nhat Pham <[email protected]>
Tested-by: Nhat Pham <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Chris Murphy <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
l1k pushed a commit that referenced this pull request Apr 4, 2025
Two fixes from the recent logging changes:

bch2_inconsistent(), bch2_fs_inconsistent() be called from interrupt
context, or with rcu_read_lock() held.

The one syzbot found is in
  bch2_bkey_pick_read_device
  bch2_dev_rcu
  bch2_fs_inconsistent

We're starting to switch to lift the printbufs up to higher levels so we
can emit better log messages and print them all in one go (avoid
garbling), so that conversion will help with spotting these in the
future; when we declare a printbuf it must be flagged if we're in an
atomic context.

Secondly, in btree_node_write_endio:

00085 BUG: sleeping function called from invalid context at include/linux/sched/mm.h:321
00085 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 618, name: bch-reclaim/fa6
00085 preempt_count: 10001, expected: 0
00085 RCU nest depth: 0, expected: 0
00085 4 locks held by bch-reclaim/fa6/618:
00085  #0: ffffff80d7ccad68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x84/0x198
00085  #1: ffffff80d7c84218 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x1c0/0x440
00085  #2: ffffff80cd3f8140 (bcachefs_btree){+.+.}-{0:0}, at: __bch2_trans_get+0x22c/0x440
00085  #3: ffffff80c3823c20 (&vblk->vqs[i].lock){-.-.}-{3:3}, at: virtblk_done+0x58/0x130
00085 irq event stamp: 328
00085 hardirqs last  enabled at (327): [<ffffffc080073a14>] finish_task_switch.isra.0+0xbc/0x2a0
00085 hardirqs last disabled at (328): [<ffffffc080971a10>] el1_interrupt+0x20/0x60
00085 softirqs last  enabled at (0): [<ffffffc08002f920>] copy_process+0x7c8/0x2118
00085 softirqs last disabled at (0): [<0000000000000000>] 0x0
00085 Preemption disabled at:
00085 [<ffffffc08003ada0>] irq_enter_rcu+0x18/0x90
00085 CPU: 8 UID: 0 PID: 618 Comm: bch-reclaim/fa6 Not tainted 6.14.0-rc6-ktest-g04630bde23e8 #18798
00085 Hardware name: linux,dummy-virt (DT)
00085 Call trace:
00085  show_stack+0x1c/0x30 (C)
00085  dump_stack_lvl+0x84/0xc0
00085  dump_stack+0x14/0x20
00085  __might_resched+0x180/0x288
00085  __might_sleep+0x4c/0x88
00085  __kmalloc_node_track_caller_noprof+0x34c/0x3e0
00085  krealloc_noprof+0x1a0/0x2d8
00085  bch2_printbuf_make_room+0x9c/0x120
00085  bch2_prt_printf+0x60/0x1b8
00085  btree_node_write_endio+0x1b0/0x2d8
00085  bio_endio+0x138/0x1f0
00085  btree_node_write_endio+0xe8/0x2d8
00085  bio_endio+0x138/0x1f0
00085  blk_update_request+0x220/0x4c0
00085  blk_mq_end_request+0x28/0x148
00085  virtblk_request_done+0x64/0xe8
00085  blk_mq_complete_request+0x34/0x40
00085  virtblk_done+0x78/0x130
00085  vring_interrupt+0x6c/0xb0
00085  __handle_irq_event_percpu+0x8c/0x2e0
00085  handle_irq_event+0x50/0xb0
00085  handle_fasteoi_irq+0xc4/0x250
00085  handle_irq_desc+0x44/0x60
00085  generic_handle_domain_irq+0x20/0x30
00085  gic_handle_irq+0x54/0xc8
00085  call_on_irq_stack+0x24/0x40

Reported-by: [email protected]
Signed-off-by: Kent Overstreet <[email protected]>
l1k pushed a commit that referenced this pull request Apr 5, 2025
v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text

Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.

Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.

I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:

    Setting pool0/active to 0
    Setting pool1/active to 1
    [   73.911067][ T4365] ibmveth 30000002 eth0: close starting
    Setting pool1/active to 1
    Setting pool1/active to 0
    [   73.911367][ T4366] ibmveth 30000002 eth0: close starting
    [   73.916056][ T4365] ibmveth 30000002 eth0: close complete
    [   73.916064][ T4365] ibmveth 30000002 eth0: open starting
    [  110.808564][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  230.808495][  T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
    [  243.683786][  T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
    [  243.683827][  T123]       Not tainted 6.14.0-01103-g2df0c02dab82-dirty torvalds#8
    [  243.683833][  T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [  243.683838][  T123] task:stress.sh       state:D stack:28096 pid:4365  tgid:4365  ppid:4364   task_flags:0x400040 flags:0x00042000
    [  243.683852][  T123] Call Trace:
    [  243.683857][  T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
    [  243.683868][  T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
    [  243.683878][  T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
    [  243.683888][  T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
    [  243.683896][  T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
    [  243.683904][  T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
    [  243.683913][  T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
    [  243.683921][  T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
    [  243.683928][  T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
    [  243.683936][  T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
    [  243.683944][  T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
    [  243.683951][  T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
    [  243.683958][  T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
    [  243.683966][  T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
    [  243.683973][  T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
    ...
    [  243.684087][  T123] Showing all locks held in the system:
    [  243.684095][  T123] 1 lock held by khungtaskd/123:
    [  243.684099][  T123]  #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
    [  243.684114][  T123] 4 locks held by stress.sh/4365:
    [  243.684119][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684132][  T123]  #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684143][  T123]  #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684155][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
    [  243.684166][  T123] 5 locks held by stress.sh/4366:
    [  243.684170][  T123]  #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
    [  243.684183][  T123]  #1: c00000000aee2288 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
    [  243.684194][  T123]  #2: c0000000366f4ba8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
    [  243.684205][  T123]  #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_disable+0x30/0x60
    [  243.684216][  T123]  #4: c0000003ff9bbf18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x138/0x12a0

From the ibmveth debug, two threads are calling veth_pool_store, which
calls ibmveth_close and ibmveth_open. Here's the sequence:

  T4365             T4366
  ----------------- ----------------- ---------
  veth_pool_store   veth_pool_store
                    ibmveth_close
  ibmveth_close
  napi_disable
                    napi_disable
  ibmveth_open
  napi_enable                         <- HANG

ibmveth_close calls napi_disable at the top and ibmveth_open calls
napi_enable at the top.

https://docs.kernel.org/networking/napi.html]] says

  The control APIs are not idempotent. Control API calls are safe
  against concurrent use of datapath APIs but an incorrect sequence of
  control API calls may result in crashes, deadlocks, or race
  conditions. For example, calling napi_disable() multiple times in a
  row will deadlock.

In the normal open and close paths, rtnl_mutex is acquired to prevent
other callers. This is missing from veth_pool_store. Use rtnl_mutex in
veth_pool_store fixes these hangs.

Signed-off-by: Dave Marquardt <[email protected]>
Fixes: 860f242 ("[PATCH] ibmveth change buffer pools dynamically")
Reviewed-by: Nick Child <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
l1k pushed a commit that referenced this pull request Apr 17, 2025
The ieee80211 skb control block key (set when skb was queued) could have
been removed before ieee80211_tx_dequeue() call. ieee80211_tx_dequeue()
already called ieee80211_tx_h_select_key() to get the current key, but
the latter do not update the key in skb control block in case it is
NULL. Because some drivers actually use this key in their TX callbacks
(e.g. ath1{1,2}k_mac_op_tx()) this could lead to the use after free
below:

  BUG: KASAN: slab-use-after-free in ath11k_mac_op_tx+0x590/0x61c
  Read of size 4 at addr ffffff803083c248 by task kworker/u16:4/1440

  CPU: 3 UID: 0 PID: 1440 Comm: kworker/u16:4 Not tainted 6.13.0-ge128f627f404 #2
  Hardware name: HW (DT)
  Workqueue: bat_events batadv_send_outstanding_bcast_packet
  Call trace:
   show_stack+0x14/0x1c (C)
   dump_stack_lvl+0x58/0x74
   print_report+0x164/0x4c0
   kasan_report+0xac/0xe8
   __asan_report_load4_noabort+0x1c/0x24
   ath11k_mac_op_tx+0x590/0x61c
   ieee80211_handle_wake_tx_queue+0x12c/0x1c8
   ieee80211_queue_skb+0xdcc/0x1b4c
   ieee80211_tx+0x1ec/0x2bc
   ieee80211_xmit+0x224/0x324
   __ieee80211_subif_start_xmit+0x85c/0xcf8
   ieee80211_subif_start_xmit+0xc0/0xec4
   dev_hard_start_xmit+0xf4/0x28c
   __dev_queue_xmit+0x6ac/0x318c
   batadv_send_skb_packet+0x38c/0x4b0
   batadv_send_outstanding_bcast_packet+0x110/0x328
   process_one_work+0x578/0xc10
   worker_thread+0x4bc/0xc7c
   kthread+0x2f8/0x380
   ret_from_fork+0x10/0x20

  Allocated by task 1906:
   kasan_save_stack+0x28/0x4c
   kasan_save_track+0x1c/0x40
   kasan_save_alloc_info+0x3c/0x4c
   __kasan_kmalloc+0xac/0xb0
   __kmalloc_noprof+0x1b4/0x380
   ieee80211_key_alloc+0x3c/0xb64
   ieee80211_add_key+0x1b4/0x71c
   nl80211_new_key+0x2b4/0x5d8
   genl_family_rcv_msg_doit+0x198/0x240
  <...>

  Freed by task 1494:
   kasan_save_stack+0x28/0x4c
   kasan_save_track+0x1c/0x40
   kasan_save_free_info+0x48/0x94
   __kasan_slab_free+0x48/0x60
   kfree+0xc8/0x31c
   kfree_sensitive+0x70/0x80
   ieee80211_key_free_common+0x10c/0x174
   ieee80211_free_keys+0x188/0x46c
   ieee80211_stop_mesh+0x70/0x2cc
   ieee80211_leave_mesh+0x1c/0x60
   cfg80211_leave_mesh+0xe0/0x280
   cfg80211_leave+0x1e0/0x244
  <...>

Reset SKB control block key before calling ieee80211_tx_h_select_key()
to avoid that.

Fixes: bb42f2d ("mac80211: Move reorder-sensitive TX handlers to after TXQ dequeue")
Signed-off-by: Remi Pommarel <[email protected]>
Link: https://patch.msgid.link/06aa507b853ca385ceded81c18b0a6dd0f081bc8.1742833382.git.repk@triplefau.lt
Signed-off-by: Johannes Berg <[email protected]>
l1k pushed a commit that referenced this pull request Apr 17, 2025
Commit 7da55c2 ("drm/amd/display: Remove incorrect FP context
start") removes the FP context protection of dml2_create(), and it said
"All the DC_FP_START/END should be used before call anything from DML2".

However, dml2_init()/dml21_init() are not protected from their callers,
causing such errors:

 do_fpu invoked from kernel context![#1]:
 CPU: 0 UID: 0 PID: 239 Comm: kworker/0:5 Not tainted 6.14.0-rc6+ #2
 Workqueue: events work_for_cpu_fn
 pc ffff80000319de80 ra ffff80000319de5c tp 900000010575c000 sp 900000010575f840
 a0 0000000000000000 a1 900000012f210130 a2 900000012f000000 a3 ffff80000357e268
 a4 ffff80000357e260 a5 900000012ea52cf0 a6 0000000400000004 a7 0000012c00001388
 t0 00001900000015e0 t1 ffff80000379d000 t2 0000000010624dd3 t3 0000006400000014
 t4 00000000000003e8 t5 0000005000000018 t6 0000000000000020 t7 0000000f00000064
 t8 000000000000002f u0 5f5e9200f8901912 s9 900000012d380010 s0 900000012ea51fd8
 s1 900000012f000000 s2 9000000109296000 s3 0000000000000001 s4 0000000000001fd8
 s5 0000000000000001 s6 ffff800003415000 s7 900000012d390000 s8 ffff800003211f80
    ra: ffff80000319de5c dml21_apply_soc_bb_overrides+0x3c/0x960 [amdgpu]
   ERA: ffff80000319de80 dml21_apply_soc_bb_overrides+0x60/0x960 [amdgpu]
  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  PRMD: 00000004 (PPLV0 +PIE -PWE)
  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
  ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
 ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0)
  PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S)
 Process kworker/0:5 (pid: 239, threadinfo=00000000927eadc6, task=000000008fd31682)
 Stack : 00040dc000003164 0000000000000001 900000012f210130 900000012eabeeb8
         900000012f000000 ffff80000319fe48 900000012f210000 900000012f210130
         900000012f000000 900000012eabeeb8 0000000000000001 ffff8000031a0064
         900000010575f9f0 900000012f210130 900000012eac0000 900000012ea80000
         900000012f000000 ffff8000031cefc4 900000010575f9f0 ffff8000035859c0
         ffff800003414000 900000010575fa78 900000012f000000 ffff8000031b4c50
         0000000000000000 9000000101c9d700 9000000109c40000 5f5e9200f8901912
         900000012d3c4bd0 900000012d3c5000 ffff8000034aed18 900000012d380010
         900000012d3c4bd0 ffff800003414000 900000012d380000 ffff800002ea49dc
         0000000000000001 900000012d3c6000 00000000ffffe423 0000000000010000
         ...
 Call Trace:
 [<ffff80000319de80>] dml21_apply_soc_bb_overrides+0x60/0x960 [amdgpu]
 [<ffff80000319fe44>] dml21_init+0xa4/0x280 [amdgpu]
 [<ffff8000031a0060>] dml21_create+0x40/0x80 [amdgpu]
 [<ffff8000031cefc0>] dc_state_create+0x100/0x160 [amdgpu]
 [<ffff8000031b4c4c>] dc_create+0x44c/0x640 [amdgpu]
 [<ffff800002ea49d8>] amdgpu_dm_init+0x3f8/0x2060 [amdgpu]
 [<ffff800002ea6658>] dm_hw_init+0x18/0x60 [amdgpu]
 [<ffff800002b16738>] amdgpu_device_init+0x1938/0x27e0 [amdgpu]
 [<ffff800002b18e80>] amdgpu_driver_load_kms+0x20/0xa0 [amdgpu]
 [<ffff800002b0c8f0>] amdgpu_pci_probe+0x1b0/0x580 [amdgpu]
 [<900000000448eae4>] local_pci_probe+0x44/0xc0
 [<9000000003b02b18>] work_for_cpu_fn+0x18/0x40
 [<9000000003b05da0>] process_one_work+0x160/0x300
 [<9000000003b06718>] worker_thread+0x318/0x440
 [<9000000003b11b8c>] kthread+0x12c/0x220
 [<9000000003ac1484>] ret_from_kernel_thread+0x8/0xa4

Unfortunately, protecting dml2_init()/dml21_init() out of DML2 causes
"sleeping function called from invalid context", so protect them with
DC_FP_START() and DC_FP_END() inside.

Fixes: 7da55c2 ("drm/amd/display: Remove incorrect FP context start")
Cc: [email protected]
Signed-off-by: Huacai Chen <[email protected]>
Reviewed-by: Aurabindo Pillai <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
l1k pushed a commit that referenced this pull request Apr 17, 2025
SMC consists of two sockets: smc_sock and kernel TCP socket.

Currently, there are two ways of creating the sockets, and syzbot reported
a lockdep splat [0] for the newer way introduced by commit d25a92c
("net/smc: Introduce IPPROTO_SMC").

  socket(AF_SMC             , SOCK_STREAM, SMCPROTO_SMC or SMCPROTO_SMC6)
  socket(AF_INET or AF_INET6, SOCK_STREAM, IPPROTO_SMC)

When a socket is allocated, sock_lock_init() sets a lockdep lock class to
sk->sk_lock.slock based on its protocol family.  In the IPPROTO_SMC case,
AF_INET or AF_INET6 lock class is assigned to smc_sock.

The repro sets IPV6_JOIN_ANYCAST for IPv6 UDP and SMC socket and exercises
smc_switch_to_fallback() for IPPROTO_SMC.

  1. smc_switch_to_fallback() is called under lock_sock() and holds
     smc->clcsock_release_lock.

      sk_lock-AF_INET6 -> &smc->clcsock_release_lock
      (sk_lock-AF_SMC)

  2. Setting IPV6_JOIN_ANYCAST to SMC holds smc->clcsock_release_lock
     and calls setsockopt() for the kernel TCP socket, which holds RTNL
     and the kernel socket's lock_sock().

      &smc->clcsock_release_lock -> rtnl_mutex (-> k-sk_lock-AF_INET6)

  3. Setting IPV6_JOIN_ANYCAST to UDP holds RTNL and lock_sock().

      rtnl_mutex -> sk_lock-AF_INET6

Then, lockdep detects a false-positive circular locking,

  .-> sk_lock-AF_INET6 -> &smc->clcsock_release_lock -> rtnl_mutex -.
  `-----------------------------------------------------------------'

but IPPROTO_SMC should have the same locking rule as AF_SMC.

      sk_lock-AF_SMC   -> &smc->clcsock_release_lock -> rtnl_mutex -> k-sk_lock-AF_INET6

Let's set the same lock class for smc_sock.

Given AF_SMC uses the same lock class for SMCPROTO_SMC and SMCPROTO_SMC6,
we do not need to separate the class for AF_INET and AF_INET6.

[0]:
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Not tainted

syz.4.1528/11571 is trying to acquire lock:
ffffffff8fef8de8 (rtnl_mutex){+.+.}-{4:4}, at: ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220

but task is already holding lock:
ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:903
       smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781
       sock_sendmsg_nosec net/socket.c:718 [inline]
       __sock_sendmsg net/socket.c:733 [inline]
       ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
       ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
       __sys_sendmsg+0x16e/0x220 net/socket.c:2659
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #1 (sk_lock-AF_INET6){+.+.}-{0:0}:
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3645
       lock_sock include/net/sock.h:1624 [inline]
       sockopt_lock_sock net/core/sock.c:1133 [inline]
       sockopt_lock_sock+0x54/0x70 net/core/sock.c:1124
       do_ipv6_setsockopt+0x2160/0x4520 net/ipv6/ipv6_sockglue.c:567
       ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993
       udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1850
       do_sock_setsockopt+0x222/0x480 net/socket.c:2303
       __sys_setsockopt+0x1a0/0x230 net/socket.c:2328
       __do_sys_setsockopt net/socket.c:2334 [inline]
       __se_sys_setsockopt net/socket.c:2331 [inline]
       __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #0 (rtnl_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain kernel/locking/lockdep.c:3906 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
       inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
       __sock_release net/socket.c:647 [inline]
       sock_release+0x8e/0x1d0 net/socket.c:675
       smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
       smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
       __sock_release+0xb0/0x270 net/socket.c:647
       sock_close+0x1c/0x30 net/socket.c:1398
       __fput+0x3ff/0xb70 fs/file_table.c:464
       task_work_run+0x14e/0x250 kernel/task_work.c:227
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
       do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  rtnl_mutex --> sk_lock-AF_INET6 --> &smc->clcsock_release_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&smc->clcsock_release_lock);
                               lock(sk_lock-AF_INET6);
                               lock(&smc->clcsock_release_lock);
  lock(rtnl_mutex);

 *** DEADLOCK ***

2 locks held by syz.4.1528/11571:
 #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
 #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
 #1: ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30

stack backtrace:
CPU: 0 UID: 0 PID: 11571 Comm: syz.4.1528 Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain kernel/locking/lockdep.c:3906 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
 ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
 inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
 __sock_release net/socket.c:647 [inline]
 sock_release+0x8e/0x1d0 net/socket.c:675
 smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
 __sock_release+0xb0/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1398
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b4b38d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4efd22d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000b14a3 RCX: 00007f8b4b38d169
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8b4b5a7ba0 R08: 0000000000000001 R09: 000000114efd25cf
R10: 00007f8b4b200000 R11: 0000000000000246 R12: 00007f8b4b5a5fac
R13: 00007f8b4b5a5fa0 R14: ffffffffffffffff R15: 00007ffe4efd23f0
 </TASK>

Fixes: d25a92c ("net/smc: Introduce IPPROTO_SMC")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=be6f4b383534d88989f7
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Wenjia Zhang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
l1k pushed a commit that referenced this pull request Apr 17, 2025
Ido Schimmel says:

====================
fib_rules: Fix iif / oif matching on L3 master device

Patch #1 fixes a recently reported regression regarding FIB rules that
match on iif / oif being a VRF device.

Patch #2 adds test cases to the FIB rules selftest.
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
twilfredo pushed a commit to twilfredo/spdm-linux that referenced this pull request Apr 30, 2025
Communicating with the hypervisor using the shared GHCB page requires
clearing the C bit in the mapping of that page. When executing in the
context of the EFI boot services, the page tables are owned by the
firmware, and this manipulation is not possible.

So switch to a different API for accepting memory in SEV-SNP guests, one
which is actually supported at the point during boot where the EFI stub
may need to accept memory, but the SEV-SNP init code has not executed
yet.

For simplicity, also switch the memory acceptance carried out by the
decompressor when not booting via EFI - this only involves the
allocation for the decompressed kernel, and is generally only called
after kexec, as normal boot will jump straight into the kernel from the
EFI stub.

Fixes: 6c32117 ("x86/sev: Add SNP-specific unaccepted memory support")
Tested-by: Tom Lendacky <[email protected]>
Co-developed-by: Tom Lendacky <[email protected]>
Signed-off-by: Tom Lendacky <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: <[email protected]>
Cc: Dionna Amalie Glaze <[email protected]>
Cc: Kevin Loughlin <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected] # discussion thread l1k#1
Link: https://lore.kernel.org/r/[email protected] # discussion thread l1k#2
Link: https://lore.kernel.org/r/[email protected] # final submission
l1k pushed a commit that referenced this pull request May 6, 2025
There is a potential deadlock if we do report zones in an IO context, detailed
in below lockdep report. When one process do a report zones and another process
freezes the block device, the report zones side cannot allocate a tag because
the freeze is already started. This can thus result in new block group creation
to hang forever, blocking the write path.

Thankfully, a new block group should be created on empty zones. So, reporting
the zones is not necessary and we can set the write pointer = 0 and load the
zone capacity from the block layer using bdev_zone_capacity() helper.

 ======================================================
 WARNING: possible circular locking dependency detected
 6.14.0-rc1 torvalds#252 Not tainted
 ------------------------------------------------------
 modprobe/1110 is trying to acquire lock:
 ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60

 but task is already holding lock:
 ffff8881205b6f20 (&q->q_usage_counter(queue)torvalds#16){++++}-{0:0}, at: sd_remove+0x85/0x130

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #3 (&q->q_usage_counter(queue)torvalds#16){++++}-{0:0}:
        blk_queue_enter+0x3d9/0x500
        blk_mq_alloc_request+0x47d/0x8e0
        scsi_execute_cmd+0x14f/0xb80
        sd_zbc_do_report_zones+0x1c1/0x470
        sd_zbc_report_zones+0x362/0xd60
        blkdev_report_zones+0x1b1/0x2e0
        btrfs_get_dev_zones+0x215/0x7e0 [btrfs]
        btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs]
        btrfs_make_block_group+0x36b/0x870 [btrfs]
        btrfs_create_chunk+0x147d/0x2320 [btrfs]
        btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs]
        start_transaction+0xce6/0x1620 [btrfs]
        btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs]
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #2 (&fs_info->dev_replace.rwsem){++++}-{4:4}:
        down_read+0x9b/0x470
        btrfs_map_block+0x2ce/0x2ce0 [btrfs]
        btrfs_submit_chunk+0x2d4/0x16c0 [btrfs]
        btrfs_submit_bbio+0x16/0x30 [btrfs]
        btree_write_cache_pages+0xb5a/0xf90 [btrfs]
        do_writepages+0x17f/0x7b0
        __writeback_single_inode+0x114/0xb00
        writeback_sb_inodes+0x52b/0xe00
        wb_writeback+0x1a7/0x800
        wb_workfn+0x12a/0xbd0
        process_one_work+0x85a/0x1460
        worker_thread+0x5e2/0xfc0
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}:
        __mutex_lock+0x1aa/0x1360
        btree_write_cache_pages+0x252/0xf90 [btrfs]
        do_writepages+0x17f/0x7b0
        __writeback_single_inode+0x114/0xb00
        writeback_sb_inodes+0x52b/0xe00
        wb_writeback+0x1a7/0x800
        wb_workfn+0x12a/0xbd0
        process_one_work+0x85a/0x1460
        worker_thread+0x5e2/0xfc0
        kthread+0x39d/0x750
        ret_from_fork+0x30/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}:
        __lock_acquire+0x2f52/0x5ea0
        lock_acquire+0x1b1/0x540
        __flush_work+0x3ac/0xb60
        wb_shutdown+0x15b/0x1f0
        bdi_unregister+0x172/0x5b0
        del_gendisk+0x841/0xa20
        sd_remove+0x85/0x130
        device_release_driver_internal+0x368/0x520
        bus_remove_device+0x1f1/0x3f0
        device_del+0x3bd/0x9c0
        __scsi_remove_device+0x272/0x340
        scsi_forget_host+0xf7/0x170
        scsi_remove_host+0xd2/0x2a0
        sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
        device_release_driver_internal+0x368/0x520
        bus_remove_device+0x1f1/0x3f0
        device_del+0x3bd/0x9c0
        device_unregister+0x13/0xa0
        sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
        scsi_debug_exit+0x17/0x70 [scsi_debug]
        __do_sys_delete_module.isra.0+0x321/0x520
        do_syscall_64+0x93/0x180
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 other info that might help us debug this:

 Chain exists of:
   (work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)torvalds#16

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&q->q_usage_counter(queue)torvalds#16);
                                lock(&fs_info->dev_replace.rwsem);
                                lock(&q->q_usage_counter(queue)torvalds#16);
   lock((work_completion)(&(&wb->dwork)->work));

  *** DEADLOCK ***

 5 locks held by modprobe/1110:
  #0: ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
  #1: ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0
  #2: ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
  #3: ffff8881205b6f20 (&q->q_usage_counter(queue)torvalds#16){++++}-{0:0}, at: sd_remove+0x85/0x130
  #4: ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60

 stack backtrace:
 CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 torvalds#252
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x6a/0x90
  print_circular_bug.cold+0x1e0/0x274
  check_noncircular+0x306/0x3f0
  ? __pfx_check_noncircular+0x10/0x10
  ? mark_lock+0xf5/0x1650
  ? __pfx_check_irq_usage+0x10/0x10
  ? lockdep_lock+0xca/0x1c0
  ? __pfx_lockdep_lock+0x10/0x10
  __lock_acquire+0x2f52/0x5ea0
  ? __pfx___lock_acquire+0x10/0x10
  ? __pfx_mark_lock+0x10/0x10
  lock_acquire+0x1b1/0x540
  ? __flush_work+0x38f/0xb60
  ? __pfx_lock_acquire+0x10/0x10
  ? __pfx_lock_release+0x10/0x10
  ? mark_held_locks+0x94/0xe0
  ? __flush_work+0x38f/0xb60
  __flush_work+0x3ac/0xb60
  ? __flush_work+0x38f/0xb60
  ? __pfx_mark_lock+0x10/0x10
  ? __pfx___flush_work+0x10/0x10
  ? __pfx_wq_barrier_func+0x10/0x10
  ? __pfx___might_resched+0x10/0x10
  ? mark_held_locks+0x94/0xe0
  wb_shutdown+0x15b/0x1f0
  bdi_unregister+0x172/0x5b0
  ? __pfx_bdi_unregister+0x10/0x10
  ? up_write+0x1ba/0x510
  del_gendisk+0x841/0xa20
  ? __pfx_del_gendisk+0x10/0x10
  ? _raw_spin_unlock_irqrestore+0x35/0x60
  ? __pm_runtime_resume+0x79/0x110
  sd_remove+0x85/0x130
  device_release_driver_internal+0x368/0x520
  ? kobject_put+0x5d/0x4a0
  bus_remove_device+0x1f1/0x3f0
  device_del+0x3bd/0x9c0
  ? __pfx_device_del+0x10/0x10
  __scsi_remove_device+0x272/0x340
  scsi_forget_host+0xf7/0x170
  scsi_remove_host+0xd2/0x2a0
  sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
  ? kernfs_remove_by_name_ns+0xc0/0xf0
  device_release_driver_internal+0x368/0x520
  ? kobject_put+0x5d/0x4a0
  bus_remove_device+0x1f1/0x3f0
  device_del+0x3bd/0x9c0
  ? __pfx_device_del+0x10/0x10
  ? __pfx___mutex_unlock_slowpath+0x10/0x10
  device_unregister+0x13/0xa0
  sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
  scsi_debug_exit+0x17/0x70 [scsi_debug]
  __do_sys_delete_module.isra.0+0x321/0x520
  ? __pfx___do_sys_delete_module.isra.0+0x10/0x10
  ? __pfx_slab_free_after_rcu_debug+0x10/0x10
  ? kasan_save_stack+0x2c/0x50
  ? kasan_record_aux_stack+0xa3/0xb0
  ? __call_rcu_common.constprop.0+0xc4/0xfb0
  ? kmem_cache_free+0x3a0/0x590
  ? __x64_sys_close+0x78/0xd0
  do_syscall_64+0x93/0x180
  ? lock_is_held_type+0xd5/0x130
  ? __call_rcu_common.constprop.0+0x3c0/0xfb0
  ? lockdep_hardirqs_on+0x78/0x100
  ? __call_rcu_common.constprop.0+0x3c0/0xfb0
  ? __pfx___call_rcu_common.constprop.0+0x10/0x10
  ? kmem_cache_free+0x3a0/0x590
  ? lockdep_hardirqs_on_prepare+0x16d/0x400
  ? do_syscall_64+0x9f/0x180
  ? lockdep_hardirqs_on+0x78/0x100
  ? do_syscall_64+0x9f/0x180
  ? __pfx___x64_sys_openat+0x10/0x10
  ? lockdep_hardirqs_on_prepare+0x16d/0x400
  ? do_syscall_64+0x9f/0x180
  ? lockdep_hardirqs_on+0x78/0x100
  ? do_syscall_64+0x9f/0x180
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f436712b68b
 RSP: 002b:00007ffe9f1a8658 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
 RAX: ffffffffffffffda RBX: 00005559b367fd80 RCX: 00007f436712b68b
 RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00005559b367fde8
 RBP: 00007ffe9f1a8680 R08: 1999999999999999 R09: 0000000000000000
 R10: 00007f43671a5fe0 R11: 0000000000000206 R12: 0000000000000000
 R13: 00007ffe9f1a86b0 R14: 0000000000000000 R15: 0000000000000000
  </TASK>

Reported-by: Shin'ichiro Kawasaki <[email protected]>
CC: <[email protected]> # 6.13+
Tested-by: Shin'ichiro Kawasaki <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Signed-off-by: Naohiro Aota <[email protected]>
Signed-off-by: David Sterba <[email protected]>
l1k pushed a commit that referenced this pull request May 6, 2025
[BUG]
There is a bug report that a syzbot reproducer can lead to the following
busy inode at unmount time:

  BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50
  VFS: Busy inodes after unmount of loop1 (btrfs)
  ------------[ cut here ]------------
  kernel BUG at fs/super.c:650!
  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
  CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full)
  Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650
  Call Trace:
   <TASK>
   kill_anon_super+0x3a/0x60 fs/super.c:1237
   btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099
   deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
   deactivate_super fs/super.c:506 [inline]
   deactivate_super+0xe2/0x100 fs/super.c:502
   cleanup_mnt+0x21f/0x440 fs/namespace.c:1435
   task_work_run+0x14d/0x240 kernel/task_work.c:227
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
   exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
   __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
   syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218
   do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

[CAUSE]
When btrfs_alloc_path() failed, btrfs_iget() directly returned without
releasing the inode already allocated by btrfs_iget_locked().

This results the above busy inode and trigger the kernel BUG.

[FIX]
Fix it by calling iget_failed() if btrfs_alloc_path() failed.

If we hit error inside btrfs_read_locked_inode(), it will properly call
iget_failed(), so nothing to worry about.

Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a
break of the normal error handling scheme, let's fix the obvious bug
and backport first, then rework the error handling later.

Reported-by: Penglei Jiang <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 7c855e1 ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()")
CC: [email protected] # 6.13+
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Penglei Jiang <[email protected]>
Signed-off-by: David Sterba <[email protected]>
l1k pushed a commit that referenced this pull request May 6, 2025
…ux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.15, round #2

 - Single fix for broken usage of 'multi-MIDR' infrastructure in PI
   code, adding an open-coded erratum check for everyone's favorite pile
   of sand: Cavium ThunderX
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