1021932 - array buffer data leaks on early return from MediaBufferDecoder::AsyncDecodeMedia()

Status: RESOLVED FIXED

(Core :: Web Audio, defect, P1)

Description

[Andrew McCreight [:mccr8]]

I'm seeing this consistently in LSAN runs of M1:

Direct leak of 34 byte(s) in 1 object(s) allocated from:
    #0 0x471fbb in realloc /builds/slave/moz-toolchain/src/llvm/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:95
    #1 0x7f2f4c9eabe2 in js_realloc /build/obj-firefox/js/src/../../dist/include/js/Utility.h:116
    #2 0x7f2f4c9eabe2 in AllocateArrayBufferContents(JSContext*, unsigned int, void*, unsigned long) /build/js/src/vm/ArrayBufferObject.cpp:281
    #3 0x7f2f48f285fe in length /build/content/base/src/nsXMLHttpRequest.cpp:3965
    #4 0x7f2f48f285fe in nsXMLHttpRequest::OnStopRequest(nsIRequest*, nsISupports*, tag_nsresult) /build/content/base/src/nsXMLHttpRequest.cpp:2225
    #5 0x7f2f48dbd4fe in nsCORSListenerProxy::OnStopRequest(nsIRequest*, nsISupports*, tag_nsresult) /build/content/base/src/nsCrossSiteListenerProxy.cpp:655
    #6 0x7f2f455bbb5b in nsStreamListenerTee::OnStopRequest(nsIRequest*, nsISupports*, tag_nsresult) /build/netwerk/base/src/nsStreamListenerTee.cpp:53

It could be a dupe of bug 1021126, because the stack looks similar.

Comment 1

[Andrew McCreight [:mccr8]]

This is happening when running Web Audio tests.  Locally, I now see two sort of similar leaks when running this directory, and on try I see a third larger one, though that third one may not be from web audio.  I'll bisect it some more tomorrow.

Comment 2

[Andrew McCreight [:mccr8]]

Attachment: leaking allocation stacks

Comment 3

[Andrew McCreight [:mccr8]]

The JS_StealArrayBufferContents leak is from test_bug845960.html

Comment 4

[Andrew McCreight [:mccr8]]

The nsXMLHttpRequest::OnStopRequest leak seems to be from test_mediaDecoding.html, though it is hard to tell because once I run it without a number of other tests, then it just hangs..

Comment 5

[Andrew McCreight [:mccr8]]

I think I figured out the leak in test_bug845960.html.  In mozilla::dom::AudioContext::DecodeAudioData, we get a new array buffer back, which we then pass into MediaBufferDecoder::AsyncDecodeMedia() as aBuffer.  Then we fail, and hit the first return, without freeing aBuffer.  Putting a free(aBuffer); before that first return fixes the leak, but is almost certainly wrong.  The second return in that method seems to have the same problem.

The other leaks don't have DecodeAudioData in their stacks, so they are probably a different issue.  I'll file new bugs.

Comment 6

[Andrew McCreight [:mccr8]]

I filed bug 1023585 and bug 1023583 for the other leaks.

Comment 7

[Andrew McCreight [:mccr8]]

Attachment: Free the buffer on failure in MediaBufferDecoder::AsyncDecodeMedia.

https://tbpl.mozilla.org/?tree=Try&rev=0ccdd76a5338

Comment 8

[Andrew McCreight [:mccr8]]

Comment on attachment 8442406 [details] [diff] [review]
Free the buffer on failure in MediaBufferDecoder::AsyncDecodeMedia.

try run was green

Comment 9

[Andrew McCreight [:mccr8]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/e3ab11ba56a5

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/e3ab11ba56a5

Comment 11

[Jesse Ruderman]

You forgot to remove the entry from lsan_suppressions.txt

Comment 12

[Andrew McCreight [:mccr8]]

Ah, right.  The suppression can't actually be removed yet because there are two other places this leaks, but I'll remove the comment that refers to this bug once I locally confirm this particular leak is gone.

Comment 13

[Andrew McCreight [:mccr8]]

Attachment: Remove the comments about two array buffer leaks that are no longer present. r=erahm DONTBUILD

I guess I should get review on this. I did a local LSan run, and two of these leaks are no longer present, so I removed them from the comment.

Comment 14

[Andrew McCreight [:mccr8]]

Thanks for the review.

https://hg.mozilla.org/integration/mozilla-inbound/rev/9a39c61d2403

Comment 15

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/9a39c61d2403