<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[198335] trunk/Source/WebCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/198335">198335</a></dd>
<dt>Author</dt> <dd>antti@apple.com</dd>
<dt>Date</dt> <dd>2016-03-17 10:02:14 -0700 (Thu, 17 Mar 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>DataURLDecoder::DecodingResultDispatcher may get deleted outside main thread
https://bugs.webkit.org/show_bug.cgi?id=155584
rdar://problem/24492104
Reviewed by Chris Dumez.
This is unsafe as it owns strings and other types that are only safe to delete in the main thread.
* platform/network/DataURLDecoder.cpp:
(WebCore::DataURLDecoder::DecodingResultDispatcher::dispatch):
The problem is that this was a refcounted type. This created a race. If the timer fired before dispatch()
was exited the implicit deref here would trigger the deletion in the dispatching thread.
Fix by getting rid of the unnecessary refcounting. Timer firing will now delete the instance explicitly.
(WebCore::DataURLDecoder::DecodingResultDispatcher::startTimer):
(WebCore::DataURLDecoder::DecodingResultDispatcher::timerFired):</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceWebCoreChangeLog">trunk/Source/WebCore/ChangeLog</a></li>
<li><a href="#trunkSourceWebCoreplatformnetworkDataURLDecodercpp">trunk/Source/WebCore/platform/network/DataURLDecoder.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/ChangeLog (198334 => 198335)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/ChangeLog 2016-03-17 16:43:41 UTC (rev 198334)
+++ trunk/Source/WebCore/ChangeLog 2016-03-17 17:02:14 UTC (rev 198335)
</span><span class="lines">@@ -1,3 +1,24 @@
</span><ins>+2016-03-17 Antti Koivisto <antti@apple.com>
+
+ DataURLDecoder::DecodingResultDispatcher may get deleted outside main thread
+ https://bugs.webkit.org/show_bug.cgi?id=155584
+ rdar://problem/24492104
+
+ Reviewed by Chris Dumez.
+
+ This is unsafe as it owns strings and other types that are only safe to delete in the main thread.
+
+ * platform/network/DataURLDecoder.cpp:
+ (WebCore::DataURLDecoder::DecodingResultDispatcher::dispatch):
+
+ The problem is that this was a refcounted type. This created a race. If the timer fired before dispatch()
+ was exited the implicit deref here would trigger the deletion in the dispatching thread.
+
+ Fix by getting rid of the unnecessary refcounting. Timer firing will now delete the instance explicitly.
+
+ (WebCore::DataURLDecoder::DecodingResultDispatcher::startTimer):
+ (WebCore::DataURLDecoder::DecodingResultDispatcher::timerFired):
+
</ins><span class="cx"> 2016-03-17 Commit Queue <commit-queue@webkit.org>
</span><span class="cx">
</span><span class="cx"> Unreviewed, rolling out r198201.
</span></span></pre></div>
<a id="trunkSourceWebCoreplatformnetworkDataURLDecodercpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/platform/network/DataURLDecoder.cpp (198334 => 198335)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/platform/network/DataURLDecoder.cpp 2016-03-17 16:43:41 UTC (rev 198334)
+++ trunk/Source/WebCore/platform/network/DataURLDecoder.cpp 2016-03-17 17:02:14 UTC (rev 198335)
</span><span class="lines">@@ -56,11 +56,12 @@
</span><span class="cx">
</span><span class="cx"> #if HAVE(RUNLOOP_TIMER)
</span><span class="cx">
</span><del>-class DecodingResultDispatcher : public ThreadSafeRefCounted<DecodingResultDispatcher> {
</del><ins>+class DecodingResultDispatcher {
+ WTF_MAKE_FAST_ALLOCATED;
</ins><span class="cx"> public:
</span><span class="cx"> static void dispatch(std::unique_ptr<DecodeTask> decodeTask)
</span><span class="cx"> {
</span><del>- Ref<DecodingResultDispatcher> dispatcher = adoptRef(*new DecodingResultDispatcher(WTFMove(decodeTask)));
</del><ins>+ auto* dispatcher = new DecodingResultDispatcher(WTFMove(decodeTask));
</ins><span class="cx"> dispatcher->startTimer();
</span><span class="cx"> }
</span><span class="cx">
</span><span class="lines">@@ -73,8 +74,6 @@
</span><span class="cx">
</span><span class="cx"> void startTimer()
</span><span class="cx"> {
</span><del>- // Keep alive until the timer has fired.
- ref();
</del><span class="cx"> m_timer.startOneShot(0);
</span><span class="cx"> m_timer.schedule(m_decodeTask->scheduleContext.scheduledPairs);
</span><span class="cx"> }
</span><span class="lines">@@ -86,7 +85,7 @@
</span><span class="cx"> else
</span><span class="cx"> m_decodeTask->completionHandler({ });
</span><span class="cx">
</span><del>- deref();
</del><ins>+ delete this;
</ins><span class="cx"> }
</span><span class="cx">
</span><span class="cx"> RunLoopTimer<DecodingResultDispatcher> m_timer;
</span></span></pre>
</div>
</div>
</body>
</html>