Bug 187382

Summary:

[Crash] Illegal use of uninitialized std::optional value in WebCore::AnimationBase::updateStateMachine

Product:

WebKit

Reporter:

Frédéric Wang (:fredw) <fred.wang>

Component:

Animations

Assignee:

Frédéric Wang (:fredw) <fred.wang>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

cgarcia, commit-queue, dino, dstockwell, ews-watchlist, graouts, mcatanzaro, simon.fraser, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

See Also:

https://bugs.webkit.org/show_bug.cgi?id=186536

Attachments:

Description	Flags
Patch	none

Description Frédéric Wang (:fredw) 2018-07-06 02:10:00 PDT

See bug 186536 comment 41 for a repro case with Google drive and stack trace. With the patch from bug 186536, the crash happens here:

        case AnimationState::PausedWaitTimer:
            ASSERT(input == AnimationStateInput::PlayStateRunning);
            ASSERT(paused());
            // Update the times
            m_startTime = m_startTime.value(0) + beginAnimationUpdateTime() - m_pauseTime.value_or(0);
            m_pauseTime = std::nullopt;

Checking other potential misuses of uninitialized std::optional members in AnimationBase::updateStateMachine(), I only see one possible other place.

I'll just use value_or(0) for these two places to workaround these issues. Antoine Quint mentioned that the old animation code is going to be removed soon, so the actual way we fix these should not be a big deal...

Comment 1 Frédéric Wang (:fredw) 2018-07-06 02:15:29 PDT

Created attachment 344410 [details]
Patch

Comment 2 WebKit Commit Bot 2018-07-06 03:10:56 PDT

Comment on attachment 344410 [details]
Patch

Clearing flags on attachment: 344410

Committed r233574: <https://trac.webkit.org/changeset/233574>

Comment 3 WebKit Commit Bot 2018-07-06 03:10:58 PDT

All reviewed patches have been landed.  Closing bug.

Comment 4 Radar WebKit Bug Importer 2018-07-06 03:12:23 PDT

<rdar://problem/41885732>