Bug 302197 – Potential null dereference of m_target in ResizeObservation::computeTargetLocation()

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Chris Dumez]

Potential null dereference of m_target in ResizeObservation::computeTargetLocation():
```
Thread 0 Crashed::  Dispatch queue: com.apple.main-thread:
0   WebCore                       	       0x1b33a46a4 WTFCrashWithInfo(int, char const*, char const*, int) + 24
1   WebCore                       	       0x1b33a46a4 WTF::WeakPtr<WebCore::Element, WebCore::WeakPtrImplWithEventTargetData, WTF::RawPtrTraits<WebCore::WeakPtrImplWithEventTargetData>>::operator->() const + 24
2   WebCore                       	       0x1b33a46a4 WebCore::ResizeObservation::computeTargetLocation() const + 24
3   WebCore                       	       0x1b33a46a4 WebCore::ResizeObservation::computeContentRect() const + 24
4   WebCore                       	       0x1b33a46a4 _ZZN7WebCore14ResizeObserver19deliverObservationsEvENK3$_0clIKN3WTF3RefINS_17ResizeObservationENS3_12RawPtrTraitsIS5_EENS3_21DefaultRefDerefTraitsIS5_EEEEEEDaRT_ + 24
5   WebCore                       	       0x1b33a46a4 WTF::Vector<WTF::Ref<WebCore::ResizeObserverEntry, WTF::RawPtrTraits<WebCore::ResizeObserverEntry>, WTF::DefaultRefDerefTraits<WebCore::ResizeObserverEntry>>, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc> WTF::Vector<WTF::Ref<WebCore::ResizeObservation, WTF::RawPtrTraits<WebCore::ResizeObservation>, WTF::DefaultRefDerefTraits<WebCore::ResizeObservation>>, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>::map<WTF::Vector<WTF::Ref<WebCore::ResizeObserverEntry, WTF::RawPtrTraits<WebCore::ResizeObserverEntry>, WTF::DefaultRefDerefTraits<WebCore::ResizeObserverEntry>>, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>, WebCore::ResizeObserver::deliverObservations()::$_0>(WebCore::ResizeObserver::deliverObservations()::$_0 const&) const + 24
6   WebCore                       	       0x1b33a46a4 WTF::Vector<std::__1::invoke_result<WebCore::ResizeObserver::deliverObservations()::$_0, WTF::Ref<WebCore::ResizeObservation, WTF::RawPtrTraits<WebCore::ResizeObservation>, WTF::DefaultRefDerefTraits<WebCore::ResizeObservation>> const&>::type, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc> WTF::Vector<WTF::Ref<WebCore::ResizeObservation, WTF::RawPtrTraits<WebCore::ResizeObservation>, WTF::DefaultRefDerefTraits<WebCore::ResizeObservation>>, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc>::map<WebCore::ResizeObserver::deliverObservations()::$_0>(WebCore::ResizeObserver::deliverObservations()::$_0 const&) const + 24
```

[Chris Dumez]

<rdar://164271295>

[Chris Dumez]

Pull request: https://github.com/WebKit/WebKit/pull/53625

[EWS]

Committed 302765@main (a1c0f13ff6a0): <https://commits.webkit.org/302765@main>

Reviewed commits have been landed. Closing PR #53625 and removing active labels.