Crashed at FIRComponentContainer on 6.7.0

[pot8os]

[REQUIRED] Step 2: Describe your environment

• Firebase SDK version: 6.7.0
• Firebase Component: Below is from my Podfile.

    pod 'Firebase/Core', '~> 6.0'
    pod 'Firebase/AdMob'
    pod 'Firebase/Auth'
    pod 'Google-Mobile-Ads-SDK'
    pod 'Firebase/Messaging'
    pod 'Firebase/Functions'
    pod 'Firebase/RemoteConfig'
    pod 'Firebase/Performance'

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

Not sure how to reproduce so far, I just found some users of my app got this crash due to this issue. Seems it accesses non-existent key against cached instances.

firebase-ios-sdk/Firebase/Core/FIRComponentContainer.m

Line 150 in bb563c8

id cachedInstance = self.cachedInstances[protocolName];

Crashed: com.google.perf.FPREventsQueue
0  libobjc.A.dylib              0x223548d68 objc_msgSend + 8
1  CoreFoundation               0x22424bb60 -[__NSDictionaryM objectForKeyedSubscript:] + 212
2  MyApp                        0x104e26d78 -[FIRComponentContainer instanceForProtocol:] + 150 (FIRComponentContainer.m:150)
3  MyApp                        0x104e2710c +[FIRComponentType instanceForProtocol:inContainer:] + 25 (FIRComponentType.m:25)
4  MyApp                        0x104ef7eac -[FIRRemoteConfigComponent remoteConfigForNamespace:] + 4380917420
5  MyApp                        0x104ef4438 +[FIRRemoteConfig remoteConfigWithFIRNamespace:app:] + 4380902456
6  MyApp                        0x104e714c0 __38+[FPRRemoteConfigFlags sharedInstance]_block_invoke + 4380366016
7  ???                          0x223d9a484 (Missing)
8  ???                          0x223d6a234 (Missing)
9  MyApp                        0x104e71468 +[FPRRemoteConfigFlags sharedInstance] + 4380365928
10 MyApp                        0x104e702cc -[FPRConfigurations setupRemoteConfigFlags] + 4380361420
11 MyApp                        0x104e7020c -[FPRConfigurations update] + 4380361228
12 MyApp                        0x104e73500 __42-[FPRClient startWithConfiguration:error:]_block_invoke + 4380374272
(snip)

I'd like to help as much as possible if needed. Thanks!

[google-oss-bot]

I found a few problems with this issue:

• I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.
• This issue does not seem to follow the issue template. Make sure you provide all the required information.

[ryanwilson]

Hi @pot8os thanks for the report, and sorry you're seeing these crashes.

Some other information that would be very helpful:

• How many users (approximate number) are seeing this? Single digits, tens, hundreds, thousands, more?
• Is there any particular device that is crashing?
• Which iOS versions are affected?

Thanks, we're looking into this now and will keep you in the loop with how things are going. I'm not sure off the top of my head why this particular line of code would be crashing, is there a larger stack trace you could share?

[pot8os]

Thanks for your quick response @ryanwilson !

• How many users (approximate number) are seeing this? Single digits, tens, hundreds, thousands, more?

It's not many right now. My app has apx 100,000 active users per week, and I see just 8 crashes due to this.

• Is there any particular device that is crashing?
• Which iOS versions are affected?

Seems there is no bias. It happened on iPhoneX, 8 and 7 with iOS 12 and 11.

is there a larger stack trace you could share?

The reason why I snipped some was all of the lines had (Missing) so no values. I could give a permanent link for Firebase Crashlytics of my app if you could accept DM.

[nfrydenholm]

We see the same crash in a "phased app release" that we just started yesterday (where one of the changes were upgrading to Firebase 6.7.0)
It's still early numbers as not that many users has installed the new app yet, but it seems pretty serious with the 1,37% of users being impacted at this moment.

update
We have paused the phased rollout, as the numbers keep climbing. (But I haven't been able to actually reproduce it, so I cannot pitch in with any steps on how to reproduce it.)

[renanvs]

We have the same problem. This crash affect 390 users in last 3 days after submit a new release.

[vbrittes]

Same here.

43 occurrences:

5 occurrences:

[rodrigomarcelino]

I'm having the same problem. It has been affected 1400 users in 3 days.

Falha: com.google.perf.FPREventsQueue
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000010
-[FIRComponentContainer instanceForProtocol:]

0
libobjc.A.dylib
objc_msgSend + 16
1
CoreFoundation
-[__NSDictionaryM objectForKeyedSubscript:] + 216
2
MobileApp
FIRComponentContainer.m - Linha 150
-[FIRComponentContainer instanceForProtocol:] + 150
3
MobileApp
FIRComponentType.m - Linha 25
+[FIRComponentType instanceForProtocol:inContainer:] + 25
4
MobileApp
FIRExperimentController.m - Linha 173
+[FIRExperimentController sharedInstance] + 173
5
MobileApp
-[FIRRemoteConfig initWithAppName:FIROptions:namespace:DBManager:configContent:analytics:] + 4349424704
6
MobileApp
-[FIRRemoteConfigComponent remoteConfigForNamespace:] + 4349439160
7
MobileApp
+[FIRRemoteConfig remoteConfigWithFIRNamespace:app:] + 4349423896
8
MobileApp
__38+[FPRRemoteConfigFlags sharedInstance]_block_invoke + 4348886304
9
libdispatch.dylib
_dispatch_client_callout + 16
10
libdispatch.dylib
_dispatch_once_callout + 28
11
MobileApp
+[FPRRemoteConfigFlags sharedInstance] + 4348886216
12
MobileApp
-[FPRConfigurations setupRemoteConfigFlags] + 4348881708
13
MobileApp
-[FPRConfigurations update] + 4348881516
14
MobileApp
__42-[FPRClient startWithConfiguration:error:]_block_invoke + 4348894564
15
libdispatch.dylib
_dispatch_call_block_and_release + 24
21
libsystem_pthread.dylib
start_wqthread + 4

============================================================

Falha: com.apple.main-thread
SIGABRT ABORT 0x000000018bf970dc
0
libsystem_kernel.dylib
__pthread_kill + 8
7
CoreFoundation
-[__NSDictionaryM setObject:forKeyedSubscript:] + 428
8
MobileApp
FIRComponentContainer.m - Linha 139
-[FIRComponentContainer instantiateInstanceForProtocol:withBlock:] + 139
9
MobileApp
FIRComponentContainer.m - Linha 157
-[FIRComponentContainer instanceForProtocol:] + 157
10
MobileApp
FIRComponentType.m - Linha 25
+[FIRComponentType instanceForProtocol:inContainer:] + 25
11
MobileApp
FIRExperimentController.m - Linha 173
+[FIRExperimentController sharedInstance] + 173
12
MobileApp
-[FIRRemoteConfig initWithAppName:FIROptions:namespace:DBManager:configContent:analytics:] + 4302648384
13
MobileApp
-[FIRRemoteConfigComponent remoteConfigForNamespace:] + 4302662840
14
MobileApp
+[FIRRemoteConfig remoteConfigWithFIRNamespace:app:] + 4302647576
15
MobileApp
+[FIRRemoteConfig remoteConfig] + 4302647768
16
MobileApp
WMFirebaseManager.swift - Linha 120
specialized static WMFirebaseManager.start() + 120
17
MobileApp
AppDelegate.swift - Linha 94
AppDelegate.application(:didFinishLaunchingWithOptions:) + 94
18
MobileApp
- Linha 0
@objc AppDelegate.application(:didFinishLaunchingWithOptions:)
19
UIKitCore
-[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 412
48
UIKitCore
UIApplicationMain + 212
49
MobileApp
AppDelegate.swift - Linha 13
main + 13
50
libdyld.dylib
start + 4

[ryanwilson]

Thanks everyone for the feedback and sorry for the troubles. It looks like a multithreading issue between Perf and Remote Config - we'll need to make sure the FIRComponentContainer has proper guards around the internal data structure.

In the meantime, if anybody manages to reproduce this it'll greatly help verifying a solution. This is top priority for us and we hope to have a proposed fix in the next day or so for folks to test.

[nfrydenholm]

@ryanwilson I guess the two different crashes are very close related? (The one on line 139 and the other on line 150)

We see that the one one line 139 happens 3 times as frequently as the other.
And the one on line 150 only happens for iOS 12 users, where as the other one happens for iOS 10,11,12 and 13. Of course that can also explain the factor between the two frequencies.

Here are some more details for the one happening on line 150 (in case it can be of any help)
dk.dba.app_issue_crash_611e44e8de6645a5a92c33934cedc5d1_DNE_0_v2.txt