1845764 - Disable some diagnostic asserts in MediaPlaybackStatus for IPC fuzzing

Status: RESOLVED FIXED

(Core :: Audio/Video, defect, P2)

Description

[Christian Holler (:decoder)]

There is a set of diagnostic asserts here

https://searchfox.org/mozilla-central/rev/00e6644d0db8acf9372702324151b8077a3d2bb7/dom/media/mediacontrol/MediaPlaybackStatus.h#83-106

that do not hold under IPC fuzzing. As discussed with :alwu, these have no security implication and we can ignore them for IPC fuzzing.

Comment 1

[Christian Holler (:decoder)]

Attachment: Bug 1845764 - Disable asserts in MediaPlaybackStatus for IPC fuzzing. r?alwu

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit BugBot documentation.

Comment 3

[Christian Holler (:decoder)]

Per comment in review, I've looked once more at how exactly this assert is violated and I believe it is pretty simple:

The content process can call ContentParent::RecvNotifyMediaAudibleChanged via IPC and claim something is audible even though nothing is playing. That will break the MOZ_DIAGNOSTIC_ASSERT(mAudibleMediaNum < mPlayingMediaNum); assert.

You can also call this method and claim something is no longer audible even though nothing was audible in the first place, violating another of these asserts.

A well-behaved content process would do neither of these but in IPC fuzzing we can just call anything randomly.

:alwu, does that that clarify well enough how these asserts get violated in IPC fuzzing? We can reproduce these but the steps to reproduce are still rather elaborate at the moment.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5b32b268a64d
Disable asserts in MediaPlaybackStatus for IPC fuzzing. r=alwu

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/5b32b268a64d

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.