perf/x86/intel/pt: Do validate the size of a kernel address filter

Right now, the kernel address filters in PT are prone to integer overflow
that may happen in adding filter's size to its offset to obtain the end
of the range. Such an overflow would also throw a #GP in the PT event
configuration path.

Fix this by explicitly validating the result of this calculation.

Reported-by: Adrian Hunter <[email protected]>
Signed-off-by: Alexander Shishkin <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected] # v4.7
Cc: [email protected]#v4.7
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: virtuoso

arch/x86/events/intel/pt.c

@@ -1089,8 +1089,13 @@ static int pt_event_addr_filters_validate(struct list_head *filters)
 		if (!filter->range || !filter->size)
 			return -EOPNOTSUPP;
 
-		if (!filter->inode && !valid_kernel_ip(filter->offset))
-			return -EINVAL;
+		if (!filter->inode) {
+			if (!valid_kernel_ip(filter->offset))
+				return -EINVAL;
+
+			if (!valid_kernel_ip(filter->offset + filter->size))
+				return -EINVAL;
+		}
 
 		if (++range > pt_cap_get(PT_CAP_num_address_ranges))
 			return -EOPNOTSUPP;