Changeset 203909 in webkit

Timestamp:

Jul 29, 2016 11:45:15 AM (8 years ago)

Author:

rniwa@webkit.org

Message:

Crash with an Invalid Web Process IPC Message ID: WebPageProxy.AttributedStringForCharacterRangeCallback
​https://bugs.webkit.org/show_bug.cgi?id=160334
<rdar://problem/27078089>

Reviewed by Alexey Proskuryakov.

The crash is most likely caused by an MESSAGE_CHECK failure in WebPageProxy::attributedStringForCharacterRangeCallback
which marks the currently dispatching message was invalid inside the macro.

Make sure we never fail this check by sending an empty EditingRange in attributedSubstringForCharacterRangeAsync when
the editing range we're about to send to the UIProcess is invalid in WebProcess.

Unfortunately, no new tests since we don't have any reproduction and I couldn't spot any code path in which we end up
with an invalid EditingRage here with multiple inspection of the relevant code.

• WebProcess/WebPage/mac/WebPageMac.mm:

(WebKit::WebPage::attributedSubstringForCharacterRangeAsync):

Location:

trunk/Source/WebKit2

Files:

• ChangeLog (modified) (1 diff)
• WebProcess/WebPage/mac/WebPageMac.mm (modified) (1 diff)

trunk/Source/WebKit2/ChangeLog

@@ +1 @@
+2016-07-28  Ryosuke Niwa  <rniwa@webkit.org>
+
+        Crash with an Invalid Web Process IPC Message ID: WebPageProxy.AttributedStringForCharacterRangeCallback
+        https://bugs.webkit.org/show_bug.cgi?id=160334
+        <rdar://problem/27078089>
+
+        Reviewed by Alexey Proskuryakov.
+
+        The crash is most likely caused by an MESSAGE_CHECK failure in WebPageProxy::attributedStringForCharacterRangeCallback
+        which marks the currently dispatching message was invalid inside the macro.
+
+        Make sure we never fail this check by sending an empty EditingRange in attributedSubstringForCharacterRangeAsync when
+        the editing range we're about to send to the UIProcess is invalid in WebProcess.
+
+        Unfortunately, no new tests since we don't have any reproduction and I couldn't spot any code path in which we end up
+        with an invalid EditingRage here with multiple inspection of the relevant code.
+
+        * WebProcess/WebPage/mac/WebPageMac.mm:
+        (WebKit::WebPage::attributedSubstringForCharacterRangeAsync):
+
 2016-07-28  Carlos Garcia Campos  <cgarcia@igalia.com>
 

trunk/Source/WebKit2/WebProcess/WebPage/mac/WebPageMac.mm

@@ -353 +353 @@
     }
 
-    send(Messages::WebPageProxy::AttributedStringForCharacterRangeCallback(result, EditingRange(editingRange.location, [result.string length]), callbackID));
+    EditingRange rangeToSend(editingRange.location, [result.string length]);
+    ASSERT(rangeToSend.isValid());
+    if (!rangeToSend.isValid()) {
+        // Send an empty EditingRange as a last resort for <rdar://problem/27078089>.
+        send(Messages::WebPageProxy::AttributedStringForCharacterRangeCallback(result, EditingRange(), callbackID));
+        return;
+    }
+
+    send(Messages::WebPageProxy::AttributedStringForCharacterRangeCallback(result, rangeToSend, callbackID));
 }