814329 - WebRTC crash [@fim_process_event]

Status: RESOLVED FIXED

(Core :: WebRTC, defect, P1)

Description

[Christoph Diehl [:posidron]]

I am not able to reproduce this with the same testcase but am getting this exact same crash constantly after some time. The callstack above includes the output of NSPR_LOG_MODULES.

Tested with m-c changeset: 113925:20ec9014f220

Comment 1

[Christoph Diehl [:posidron]]

Attachment: callstack

Comment 3

[Scoobidiver (away)]

A space is required between @ and the signature for the connection to crash stats.

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Christoph, which testcase are you referring to in comment 0?

Comment 5

[Christoph Diehl [:posidron]]

Sorry, haven't mentioned that.
I am not able to reproduce the testcase with the same seed value during fuzzing.

Comment 6

[Randell Jesup [:jesup] (needinfo me)]

Ethan: some sort of race condition or logic flaw - can you look into it?

Cristoph: any reasonably likely way to provoke this?

Comment 7

[Randell Jesup [:jesup] (needinfo me)]

As it's a NULL-ptr deref, an assertion might help.  Or run a debug build under gdb and catch the failure

Comment 8

[Christoph Diehl [:posidron]]

(In reply to Randell Jesup [:jesup] from comment #6)
> Ethan: some sort of race condition or logic flaw - can you look into it?
> 
> Cristoph: any reasonably likely way to provoke this?

It's one of the crashes which come up during SDP fuzzing but are not reproducible with the same testcase later on.

Comment 9

[Ethan Hugg [:ehugg]]

Attachment: Protect fim_process_event from NULL input

Comment 10

[Ethan Hugg [:ehugg]]

Comment on attachment 686145 [details] [diff] [review]
Protect fim_process_event from NULL input


Uploading this patch to do some testing to see if the symptom moves if we add these checks for NULL ptrs.

Comment 11

[Ethan Hugg [:ehugg]]

Attachment: Protect fim_process_event from NULL input

Comment 12

[Ethan Hugg [:ehugg]]

Comment on attachment 688348 [details] [diff] [review]
Protect fim_process_event from NULL input


Wallpaper patch with assertions.

Comment 13

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/17278474949a