Bug 192538 – [iOS device] Crash when attempting to call -[_WKAttachment info] for an editable image

• Component: WebKit2
• Status: RESOLVED FIXED

[Wenson Hsieh]

An excerpt from the crash log, using the MobileAttachments test app:

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Subtype: KERN_INVALID_ADDRESS at 0x0000000d32538f00
VM Region Info: 0xd32538f00 is not in any region.  Bytes after previous region: 45404622593  
      REGION TYPE                      START - END             [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      MALLOC_NANO            0000000280000000-00000002a0000000 [512.0M] rw-/rwx SM=PRV  
--->  
      UNUSED SPACE AT END

Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [4000]
Triggered by Thread:  0

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   libobjc.A.dylib     objc_retain + 16
1   WebKit              -[WKDrawingView PNGRepresentation] + 76
2   WebKit              WTF::Function<WTF::RetainPtr<NSFileWrapper> ()>::CallableWrapper<WebKit::EditableImageController::associateWithAttachment(unsigned long long, WTF::String const&)::$_3>::call() + 60
3   WebKit              API::Attachment::fileWrapper() const + 80
4   WebKit              -[_WKAttachment info] + 88
5   MobileAttachments   0x104190000 + 59044
6   UIKitCore           -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 684
7   UIKitCore           -[UITableView _createPreparedCellForGlobalRow:willDisplay:] + 84
8   UIKitCore           -[UITableView _updateVisibleCellsNow:isRecursive:] + 2308
9   UIKitCore           -[UITableView layoutSubviews] + 144
10  UIKitCore           -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1428
11  libobjc.A.dylib     -[NSObject performSelector:withObject:] + 68
12  QuartzCore          -[CALayer layoutSublayers] + 188
13  QuartzCore          CA::Layer::layout_if_needed(CA::Transaction*) + 336
14  UIKitCore           -[UIView(Hierarchy) layoutBelowIfNeeded] + 560
15  UIKitCore           __86-[UISheetPresentationController setNestedPresentationIndex:withTransitionCoordinator:]_block_invoke_2 + 56
16  UIKitCore           +[UIView(Animation) performWithoutAnimation:] + 112
17  UIKitCore           __86-[UISheetPresentationController setNestedPresentationIndex:withTransitionCoordinator:]_block_invoke + 112
18  UIKitCore           -[_UIViewControllerTransitionCoordinator _applyBlocks:releaseBlocks:] + 276
19  UIKitCore           -[_UIViewControllerTransitionContext __runAlongsideAnimations] + 292
20  UIKitCore           __63+[UIView(Animation) _setAlongsideAnimations:toRunByEndOfBlock:]_block_invoke + 36
21  UIKitCore           -[UIViewAnimationState _runAlongsideAnimations] + 48

[Wenson Hsieh]

Created attachment 356912 [details]
Patch

[Tim Horton]

Comment on attachment 356912 [details]
Patch

... whoops. Also, how did I not run into this?

[WebKit Commit Bot]

Comment on attachment 356912 [details]
Patch

Clearing flags on attachment: 356912

Committed r239019: <https://trac.webkit.org/changeset/239019>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/46578922>

[Wenson Hsieh]

(In reply to Tim Horton from comment #2)
> Comment on attachment 356912 [details]
> Patch
> 
> ... whoops. Also, how did I not run into this?

Unsure :/

I am, however, able to reproduce this crash all the time without this patch. Maybe something in the OS changed? (doubtful, but possible)