1405139 - fsanitize=enum (ubsan) runtime errors for TrackInfo::TrackType

Status: RESOLVED FIXED

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

Description

[Arthur Edelstein [:arthur]]

With clang -fsanitize=enum, I see the following runtime errors in automated testing on linux64-asan. Seems to be caused by loading of stagefright_MPEG4Metadata.test_case_mp4:

 dom/media/MediaInfo.cpp:14:11 	 1 	 load of value 4294967295, which is not a valid value for type 'TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:278:35 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:281:28 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:296:7 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:300:14 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:371:32 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:374:25 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:517:13 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:544:25 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:559:13 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:582:25 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:800:11 	 1 	 load of value 4294967295, which is not a valid value for type 'TrackI
nfo::TrackType'
 media/libstagefright/binding/MP4Metadata.cpp:834:24 	 1 	 load of value 4294967295, which is not a valid value for type 'mozill
a::TrackInfo::TrackType'

Comment 1

[Arthur Edelstein [:arthur]]

Attachment: 0001-Bug-1405139-Fix-ubsan-runtime-error-for-TrackInfo-Tr.patch

Hi Gerald, I'm proposing removing these lines because I'm planning to add -fsanitize=enum in the debug build, and it disallows values outside the enum range. (See bug 1404547.) So those tests will be superfluous.

Comment 2

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Comment on attachment 8914833 [details] [diff] [review]
0001-Bug-1405139-Fix-ubsan-runtime-error-for-TrackInfo-Tr.patch

Review of attachment 8914833 [details] [diff] [review]:
-----------------------------------------------------------------

I think at the time I may have been worried that these calls could be made with a TrackType coming from the (externally-sourced) media itself, and therefore could potentially be unexpected values.
But in fact, in all instances I can see, this TrackType is explicitly specified as one of the enum constants in our code. So it should be safe not to worry about handling non-compliant enum values, as they should never happen; and these tests are indeed not necessary.

Thank you for submitting this patch.

Comment 3

[Arthur Edelstein [:arthur]]

Thanks for the review!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/6783b6208ea6
Fix ubsan runtime error for TrackInfo::TrackType. r=gerald

Comment 5

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/6783b6208ea6