Bug 168608

Summary: Nullptr dereferences when stopping a load
Product: WebKit Reporter: Brent Fulgham <bfulgham>
Component: Page LoadingAssignee: Brent Fulgham <bfulgham>
Status: RESOLVED FIXED    
Severity: Normal CC: beidson, bfulgham, cdumez, commit-queue, dbates, ddkilzer, japhet, rniwa
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch rniwa: review+

Description Brent Fulgham 2017-02-20 12:04:48 PST 
We have seen crash traces that indicate the frame is being detached from the document while stopping a load, leading to nullptr dereferences and crashes.

Other loading code anticipates the possibility the the frame is nullptr. Since these crashes are happening at the tail end of the load termination, when attempting to notify the now-detached client that the load was stopped, we should probably just recognize this is happening and avoid the dereference.
Comment 1 Brent Fulgham 2017-02-20 12:09:06 PST 
Created attachment 302163 [details]
Patch
Comment 2 Ryosuke Niwa 2017-02-20 12:14:08 PST 
Comment on attachment 302163 [details]
Patch

r=me. It's sad we can't have a test for this.
Comment 3 Brent Fulgham 2017-02-20 12:59:44 PST 
Committed r212667: <http://trac.webkit.org/changeset/212667>
Comment 4 Brent Fulgham 2017-02-20 13:00:52 PST 
<rdar://problem/29852056>