1227481 - [Static Analysis][Result of operation is garbage or undefined] Function OpenCoreDebugFiles from media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core.c

Status: RESOLVED FIXED

(Core :: WebRTC, defect)

Description

[Andi [:andi]]

The Static Analysis tool Scan-Build added warning that the left operand of > can be a garbage value in function OpenCoreDebugFiles where  aec->sampFreq is used without being initialized.

Comment 1

[Andi [:andi]]

Attachment: Bug 1227481.diff

Comment 2

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

Very low priority, and causes no problems - garbage values would merely cause either 16000 or random value between 0-15999 to be used as the wav frequency - and this would likely only be able to happen in an error path where no usable debug data would exist.  And if the file is corrupted, it's not a problem.

That said, ensuring the structure is safely allocated is worthwhile.  Though I'd use calloc perhaps instead; and clearing with "sizeof(FooStructure)" is error-prone, such as if the malloc is changed to sizeof(FooBarStructure) or sizeof(FooStructure+N).  memset(x, 0, sizeof(*x)) is safer.

Also: upstream issue; file a bug at the webrtc.org issue tracker.

Comment 3

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

Comment on attachment 8691339 [details] [diff] [review]
Bug 1227481.diff

Review of attachment 8691339 [details] [diff] [review]:
-----------------------------------------------------------------

r+ with tweak (sizeof(*aec))

Comment 4

[Andi [:andi]]

Attachment: Bug 1227481.diff

I definitely agree with you, best practice is to use sizeof(*data) in cases when you alloc more memory than the actual size of the type that data points to.

Comment 5

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/852c50e380c7

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/852c50e380c7