Changeset 243894 in webkit

Timestamp:

Apr 4, 2019, 1:31:34 PM (7 years ago)

Author:

Chris Fleizach

Message:

AX: Crash under WebCore::AccessibilityRenderObject::computeAccessibilityIsIgnored()
​https://bugs.webkit.org/show_bug.cgi?id=196600
<rdar://problem/49572996>

Reviewed by Joanmarie Diggs.

Audit AX code to not dereference renderer before checking if it's null.
Not clear how to reproduce at this time.

• accessibility/AccessibilityRenderObject.cpp:

(WebCore::webAreaIsPresentational):
(WebCore::AccessibilityRenderObject::layoutCount const):
(WebCore::AccessibilityRenderObject::widget const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• accessibility/AccessibilityRenderObject.cpp (modified) (3 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-04-04  Chris Fleizach  <cfleizach@apple.com>
+
+        AX: Crash under WebCore::AccessibilityRenderObject::computeAccessibilityIsIgnored()
+        https://bugs.webkit.org/show_bug.cgi?id=196600
+        <rdar://problem/49572996>
+
+        Reviewed by Joanmarie Diggs.
+
+        Audit AX code to not dereference renderer before checking if it's null.
+        Not clear how to reproduce at this time.
+
+        * accessibility/AccessibilityRenderObject.cpp:
+        (WebCore::webAreaIsPresentational):
+        (WebCore::AccessibilityRenderObject::layoutCount const):
+        (WebCore::AccessibilityRenderObject::widget const):
+
 2019-04-04  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/accessibility/AccessibilityRenderObject.cpp

@@ -1157 +1157 @@
 static bool webAreaIsPresentational(RenderObject* renderer)
 {
-    if (!is<RenderView>(*renderer))
+    if (!renderer || !is<RenderView>(*renderer))
         return false;
     
@@ -1446 +1446 @@
 int AccessibilityRenderObject::layoutCount() const
 {
-    if (!is<RenderView>(*m_renderer))
+    if (!m_renderer || !is<RenderView>(*m_renderer))
         return 0;
     return downcast<RenderView>(*m_renderer).frameView().layoutContext().layoutCount();
@@ -1817 +1817 @@
 Widget* AccessibilityRenderObject::widget() const
 {
-    if (!is<RenderWidget>(*m_renderer))
+    if (!m_renderer || !is<RenderWidget>(*m_renderer))
         return nullptr;
     return downcast<RenderWidget>(*m_renderer).widget();