1708801 - Crash in [@ mozilla::WebMDecoder::IsSupportedType]

Status: NEW

(Core :: Audio/Video, defect, P3)

Description

[u608768]

Crash report: https://crash-stats.mozilla.org/report/index/5ba730f5-2af3-4d1d-984b-219c20210430

Reason: EXCEPTION_PRIV_INSTRUCTION

Top 10 frames of crashing thread:

0 xul.dll static mozilla::WebMDecoder::IsSupportedType dom/media/webm/WebMDecoder.cpp:88
1  @0xfffffffffffffffe 
2 xul.dll static mozilla::dom::MediaSource::IsTypeSupported dom/media/mediasource/MediaSource.cpp:139
3 xul.dll static mozilla::dom::MediaSource::IsTypeSupported dom/media/mediasource/MediaSource.cpp:429
4 xul.dll mozilla::dom::MediaSource_Binding::isTypeSupported dom/bindings/MediaSourceBinding.cpp:798
5 xul.dll js::InternalCallOrConstruct js/src/vm/Interpreter.cpp:522
6 xul.dll Interpret js/src/vm/Interpreter.cpp:3248
7 xul.dll js::InternalCallOrConstruct js/src/vm/Interpreter.cpp:554
8 xul.dll js::jit::InvokeFromInterpreterStub js/src/jit/VMFunctions.cpp:784
9  @0x183c2431e2e 

We're seeing a number of these across all channels.

Comment 1

[Alastor Wu [:alwu]]

The crash stack looked a little weird to me, I didn't see any wrong on line#88 in WebMDecoder and the stack 1 @0xfffffffffffffffe also looked pretty strange. I found there was a similar case that also had @0xfffffffffffffffe in the crash stack in bug 1268897 and the root cause was related with NULL pointer. 0xfffffffffffffffe seems a magic number to me (not sure if that's the same as this article said)

I also checked the code callstack around WebMDecoder::IsSupportedType but didn't find anything suspicious related to NULL pointer.