1990812 - [Intermittent] Crash on canalplus.com after short playback of specific titles [@ mozilla::MediaDecoder::SetCDMProxy ]

Status: REOPENED

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

Description

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Found in

• 144.0b5

Affected versions

• 145.0a1 (2025-09-24)
• 144.0b5

Tested platforms

• Affected platforms: Windows 10/11
• Unaffected platforms: macOS 13, Ubuntu 22.04

Preconditions

• Have an account with an active subscription for Canal+

Steps to reproduce

1. Go to Canal+ and sign in with the account from prerequisites
2. From the main page, navigate to the title "BRIDGET JONES FOLLE DE LUI" and start playback (link)
3. Let the video play for a few seconds (approx. 5 seconds)
4. Click the browser's back button
5. From the main page, navigate to the title "DEXTER" and start playback (link)
6. Observe the behavior

Expected result

• The tab should not crash

Actual result

• Intermittently, the tab is crashing when starting playback of the second video

Regression range

• Uncertain if this is a regression. Due to the intermittent nature of the crash, I was unable to determine a regression range

Additional notes

• Crash report: https://crash-stats.mozilla.org/report/index/3568afdb-bc44-456b-b910-7ed6e0250925#tab-annotations
• So far, I was able to trigger the tab crash only with the titles mentioned above
• I was unable to trigger the tab crash on macOS and Ubuntu - unclear whether those platforms are unaffected or if the crash is simply intermittent

Comment 1

[Alastor Wu [:alwu]]

Could you help me capture a media profile by following this instruction? Thanks!

Comment 2

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

(In reply to Alastor Wu [:alwu] from comment #1)

Could you help me capture a media profile by following this instruction? Thanks!

Of course! Sorry for the late reply.
Here is the captured media profile: https://share.firefox.dev/3Wn1Ihm

Also attaching the crash report (in case it helps): https://crash-stats.mozilla.org/report/index/c7ef05a4-643f-4797-8b2a-0e7fe0251002

Comment 3

[Alastor Wu [:alwu]]

Thanks, will upload a patch shortly.

Comment 4

[Alastor Wu [:alwu]]

Attachment: Bug 1990812 - handle the case where switching the decoder state machine fails due to shutdown.

We will not create a new state machine if the decoder has already been shut
down. In this case, the old state machine will still report as unsupported,
which currently triggers a MOZ_DIAGNOSTIC_CRASH.

Instead of crashing, we should simply reject the promise.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/0bf980d7abf0
https://hg.mozilla.org/integration/autoland/rev/4a18cf3c4c1f
handle the case where switching the decoder state machine fails due to shutdown. r=media-playback-reviewers,chunmin

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/9c0b467506bc
https://hg.mozilla.org/integration/autoland/rev/9264f405bb4f
Revert "Bug 1990812 - handle the case where switching the decoder state machine fails due to shutdown. r=media-playback-reviewers,chunmin" for causing build bustages @MediaDecoder.cpp.

Comment 7

[agoloman]

Backed out for causing build bustages @MediaDecoder.cpp.

• Backout link
• Push with failures
• Failure Log

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/5278a541b3b5
https://hg.mozilla.org/integration/autoland/rev/3cbaa8d0b628
handle the case where switching the decoder state machine fails due to shutdown. r=media-playback-reviewers,chunmin

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/1f42324e5adc
https://hg.mozilla.org/integration/autoland/rev/d28aa98f7722
Revert "Bug 1990812 - handle the case where switching the decoder state machine fails due to shutdown. r=media-playback-reviewers,chunmin" for causing bustages on MediaDecoder.cpp

Comment 10

[Narcis Beleuzu [:NarcisB]]

Backed out for causing bustages on MediaDecoder.cpp

Backout link: https://hg-edge.mozilla.org/integration/autoland/rev/d28aa98f7722fb7b80688decb5fc79bb13c13476
Log link: https://treeherder.mozilla.org/logviewer?job_id=532816049&repo=autoland&task=GBxWPCsVQVq7ajBfF_X1hg.0&lineNumber=73027

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/4e0ba320cb1e
https://hg.mozilla.org/integration/autoland/rev/e6335c6fffd3
handle the case where switching the decoder state machine fails due to shutdown. r=media-playback-reviewers,chunmin

Comment 12

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/e6335c6fffd3

Comment 13

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected.
:alwu, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox145 to wontfix.

For more information, please visit BugBot documentation.

Comment 14

[Monica Chiorean]

I was able to reproduce the crash on Win11x64 using FF build 145.0a1(20250924094045).
Unfortunately crash still reproduces on Win11x64 using FF build 147.0a1(20251114094637), see crash https://crash-stats.mozilla.org/report/index/15771760-c52c-4bbd-b584-f65f00251114.
Reproduces on 146.0b2 see crash https://crash-stats.mozilla.org/report/index/11c439de-6b0b-4e5f-a95c-758450251114
Reopen issue.