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author | Yulong Bai <yulong.bai@qt.io> | 2019-05-21 13:48:52 +0200 |
---|---|---|
committer | Yulong Bai <yulong.bai@qt.io> | 2019-06-17 16:19:15 +0200 |
commit | e9520ec84c95e10a6826b2289e46552a2d446895 (patch) | |
tree | 74b0a97cb50c3608f82b4f3bb2cc00e115164b73 /src/quick/items/qquickitemview.cpp | |
parent | c1663865e68d96d4a51351d4d1d2bfa5f313dc18 (diff) |
Fix crash caused by objects self-destructions during displacement animations
The root cause was that the QAbstractAnimationJob::finished() might delegate its
destruction to change.listener->animationFinished(this), and the original author
was aware of that and provided a RETURN_IF_DELETE macro to return early if itself
got deleted. In the bug's case, change.listener->animationFinished(this)
dispatched to QQuickItemViewPrivate::animationFinished() which called
QQuickItemViewPrivate::release() and deleted the QAbstractAnimationJob object
itself in the end.
However, any objects derived from QAbstractAnimationJob, or holding a pointer
to a QAbstractAnimationJob, may potentially fall into the code path calling
QAbstractAnimationJob::finished(). Any QAnimationJobChangeListener that directly
or indirectly deletes QAbstractAnimationJob should be very suspicious to this
kind of "heap-use-after-free" bug. Should ensure that the QAbstractAnimationJob
won't be referenced after deletion.
In the bug's case, within the code path triggered by ListView displacement
animation, the other affected classes by QAbstractAnimationJob are:
QQuickItemViewFxItem, QQuickItemViewTransitionableItem, QQuickTransitionManager.
To fix this, a new SelfDeletable class is factored out to simplify the self-deletion
test logic. Any affected classes are made to have a public member m_selfDeletable.
Any code paths that finally reach QAbstractAnimationJob::finished() are
wrapped with related util macro.
Change-Id: Idd33fc3f2d529fd7d8bb088c329101b1e70dd6c0
Task-number: QTBUG-44308
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Diffstat (limited to 'src/quick/items/qquickitemview.cpp')
-rw-r--r-- | src/quick/items/qquickitemview.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/quick/items/qquickitemview.cpp b/src/quick/items/qquickitemview.cpp index 8dafc16cf4..2e1962bc7b 100644 --- a/src/quick/items/qquickitemview.cpp +++ b/src/quick/items/qquickitemview.cpp @@ -2225,7 +2225,10 @@ bool QQuickItemViewPrivate::prepareNonVisibleItemTransition(FxViewItem *item, co if (item->scheduledTransitionType() == QQuickItemViewTransitioner::MoveTransition) repositionItemAt(item, item->index, 0); - if (item->prepareTransition(transitioner, viewBounds)) { + bool success = false; + ACTION_IF_DELETED(item, success = item->prepareTransition(transitioner, viewBounds), return success); + + if (success) { item->releaseAfterTransition = true; return true; } |