Correct web audio-related crash in seed reports

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[Brent Fulgham]

We removed access to the Audio Processing Tap XPC service in our iOS 13 work because our testing did not show it being used in normal browsing tests. Unfortunately, it is used in some web audio cases (and games).

This patch makes two changes:

(1) It restores access to the "com.apple.coremedia.audioprocessingtap.xpc" XPC service.
(2) It checks the return value of MTAudioProcessingTapCreate (which fails when the service is blocked) and returns early to avoid using the invalid audio tap.

[Brent Fulgham]

<rdar://problem/51565203>

[Brent Fulgham]

Created attachment 374622 [details]
Patch

[Brent Fulgham]

*** Bug 200012 has been marked as a duplicate of this bug. ***

[Per Arne Vollan]

Comment on attachment 374622 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=374622&action=review

R=me.

> Source/WebKit/Resources/SandboxProfiles/ios/com.apple.WebKit.WebContent.sb:380
> +    (global-name "com.apple.coremedia.audioprocessingtap.xpc") ;; <rdar://problem/51565203>

I think the explicit allow in not needed, since it is already allowed in the imported sandbox file.

> Source/WebKit/WebProcess/com.apple.WebProcess.sb.in:609
> +       (global-name "com.apple.coremedia.audioprocessingtap.xpc") ;; <rdar://problem/51565203>

Is this needed on macOS?

[Brent Fulgham]

Created attachment 374631 [details]
Patch for landing

[Brent Fulgham]

Created attachment 374632 [details]
Patch for landing

[Alexey Proskuryakov]

*** Bug 200012 has been marked as a duplicate of this bug. ***

[WebKit Commit Bot]

Comment on attachment 374632 [details]
Patch for landing

Clearing flags on attachment: 374632

Committed r247701: <https://trac.webkit.org/changeset/247701>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.