<!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>[242917] trunk</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/242917">242917</a></dd>
<dt>Author</dt> <dd>wenson_hsieh@apple.com</dd>
<dt>Date</dt> <dd>2019-03-13 16:18:26 -0700 (Wed, 13 Mar 2019)</dd>
</dl>

<h3>Log Message</h3>
<pre>Fix an edge case where HTMLFormElement::removeFormElement is invoked twice with the same element
https://bugs.webkit.org/show_bug.cgi?id=195663
<rdar://problem/48576391>

Reviewed by Ryosuke Niwa.

Source/WebCore:

Currently, it's possible for HTMLFormControlElement's destructor to be reentrant. This may happen if the form
control element is ref'd while carrying out its destructor's logic. This may happen in two places in
HTMLFormControlElement (didChangeForm and resetDefaultButton), both of which actually don't require ensuring a
protected reference to the form control element since they should never result in any script execution.

To fix the bug, convert these strong references into raw pointers, and add ScriptDisallowedScope to ensure that
we don't change these codepaths in the future, such that they trigger arbitrary script execution.

Test: fast/forms/remove-associated-element-after-gc.html

* html/HTMLFormControlElement.cpp:
(WebCore::HTMLFormControlElement::didChangeForm):
* html/HTMLFormElement.cpp:
(WebCore::HTMLFormElement::resetDefaultButton):

LayoutTests:

Add a layout test to exercise the scenario described in the WebCore ChangeLog.

* fast/forms/remove-associated-element-after-gc-expected.txt: Added.
* fast/forms/remove-associated-element-after-gc.html: Added.</pre>

<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkLayoutTestsChangeLog">trunk/LayoutTests/ChangeLog</a></li>
<li><a href="#trunkSourceWebCoreChangeLog">trunk/Source/WebCore/ChangeLog</a></li>
<li><a href="#trunkSourceWebCorehtmlHTMLFormControlElementcpp">trunk/Source/WebCore/html/HTMLFormControlElement.cpp</a></li>
<li><a href="#trunkSourceWebCorehtmlHTMLFormElementcpp">trunk/Source/WebCore/html/HTMLFormElement.cpp</a></li>
</ul>

<h3>Added Paths</h3>
<ul>
<li><a href="#trunkLayoutTestsfastformsremoveassociatedelementaftergcexpectedtxt">trunk/LayoutTests/fast/forms/remove-associated-element-after-gc-expected.txt</a></li>
<li><a href="#trunkLayoutTestsfastformsremoveassociatedelementaftergchtml">trunk/LayoutTests/fast/forms/remove-associated-element-after-gc.html</a></li>
</ul>

</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkLayoutTestsChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/LayoutTests/ChangeLog (242916 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/ChangeLog      2019-03-13 23:07:06 UTC (rev 242916)
+++ trunk/LayoutTests/ChangeLog 2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -1,3 +1,16 @@
</span><ins>+2019-03-13  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        Fix an edge case where HTMLFormElement::removeFormElement is invoked twice with the same element
+        https://bugs.webkit.org/show_bug.cgi?id=195663
+        <rdar://problem/48576391>
+
+        Reviewed by Ryosuke Niwa.
+
+        Add a layout test to exercise the scenario described in the WebCore ChangeLog.
+
+        * fast/forms/remove-associated-element-after-gc-expected.txt: Added.
+        * fast/forms/remove-associated-element-after-gc.html: Added.
+
</ins><span class="cx"> 2019-03-13  Nikita Vasilyev  <nvasilyev@apple.com>
</span><span class="cx"> 
</span><span class="cx">         REGRESSION(r240946): Web Inspector: Styles: removing selected property doesn't update overridden status
</span></span></pre></div>
<a id="trunkLayoutTestsfastformsremoveassociatedelementaftergcexpectedtxt"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/fast/forms/remove-associated-element-after-gc-expected.txt (0 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/fast/forms/remove-associated-element-after-gc-expected.txt                             (rev 0)
+++ trunk/LayoutTests/fast/forms/remove-associated-element-after-gc-expected.txt        2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -0,0 +1 @@
</span><ins>+PASS
</ins></span></pre></div>
<a id="trunkLayoutTestsfastformsremoveassociatedelementaftergchtml"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/fast/forms/remove-associated-element-after-gc.html (0 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/fast/forms/remove-associated-element-after-gc.html                             (rev 0)
+++ trunk/LayoutTests/fast/forms/remove-associated-element-after-gc.html        2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -0,0 +1,43 @@
</span><ins>+<!DOCTYPE html>
+<html>
+<head>
+<style>
+input:default {
+    color: red;
+}
+</style>
+</head>
+<body>
+<table>
+<form><input type="submit"></form>
+</table>
+<p>This test passes if we avoid crashing, and if the green text "PASS" appears. This test requires DumpRenderTree or WebKitTestRunner.</p>
+</body>
+<script>
+if (window.testRunner) {
+    testRunner.waitUntilDone();
+    testRunner.dumpAsText();
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+    let currentIteration = 1;
+    const href = location.href;
+    const index = href.lastIndexOf("#");
+    if (index !== -1)
+        currentIteration = parseInt(href.substring(index + 1));
+
+    if (currentIteration === 5) {
+        document.writeln("<pre style='color: green'>PASS</pre>");
+        if (window.testRunner)
+            testRunner.notifyDone();
+        return;
+    }
+
+    if (window.GCController)
+        GCController.collect();
+
+    location.href = `${href.substring(0, index)}#${currentIteration + 1}`;
+    location.reload();
+}, false);
+</script>
+</html>
</ins></span></pre></div>
<a id="trunkSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/ChangeLog (242916 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/ChangeLog   2019-03-13 23:07:06 UTC (rev 242916)
+++ trunk/Source/WebCore/ChangeLog      2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -1,3 +1,26 @@
</span><ins>+2019-03-13  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        Fix an edge case where HTMLFormElement::removeFormElement is invoked twice with the same element
+        https://bugs.webkit.org/show_bug.cgi?id=195663
+        <rdar://problem/48576391>
+
+        Reviewed by Ryosuke Niwa.
+
+        Currently, it's possible for HTMLFormControlElement's destructor to be reentrant. This may happen if the form
+        control element is ref'd while carrying out its destructor's logic. This may happen in two places in
+        HTMLFormControlElement (didChangeForm and resetDefaultButton), both of which actually don't require ensuring a
+        protected reference to the form control element since they should never result in any script execution.
+
+        To fix the bug, convert these strong references into raw pointers, and add ScriptDisallowedScope to ensure that
+        we don't change these codepaths in the future, such that they trigger arbitrary script execution.
+
+        Test: fast/forms/remove-associated-element-after-gc.html
+
+        * html/HTMLFormControlElement.cpp:
+        (WebCore::HTMLFormControlElement::didChangeForm):
+        * html/HTMLFormElement.cpp:
+        (WebCore::HTMLFormElement::resetDefaultButton):
+
</ins><span class="cx"> 2019-03-13  Daniel Bates  <dabates@apple.com>
</span><span class="cx"> 
</span><span class="cx">         Remove some unnecessary !USE(UIKIT_KEYBOARD_ADDITIONS) guards
</span></span></pre></div>
<a id="trunkSourceWebCorehtmlHTMLFormControlElementcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/html/HTMLFormControlElement.cpp (242916 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/html/HTMLFormControlElement.cpp     2019-03-13 23:07:06 UTC (rev 242916)
+++ trunk/Source/WebCore/html/HTMLFormControlElement.cpp        2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -41,6 +41,7 @@
</span><span class="cx"> #include "Quirks.h"
</span><span class="cx"> #include "RenderBox.h"
</span><span class="cx"> #include "RenderTheme.h"
</span><ins>+#include "ScriptDisallowedScope.h"
</ins><span class="cx"> #include "Settings.h"
</span><span class="cx"> #include "StyleTreeResolver.h"
</span><span class="cx"> #include "ValidationMessage.h"
</span><span class="lines">@@ -557,8 +558,10 @@
</span><span class="cx"> 
</span><span class="cx"> void HTMLFormControlElement::didChangeForm()
</span><span class="cx"> {
</span><ins>+    ScriptDisallowedScope::InMainThread scriptDisallowedScope;
+
</ins><span class="cx">     FormAssociatedElement::didChangeForm();
</span><del>-    if (RefPtr<HTMLFormElement> form = this->form()) {
</del><ins>+    if (auto* form = this->form()) {
</ins><span class="cx">         if (m_willValidateInitialized && m_willValidate && !isValidFormControlElement())
</span><span class="cx">             form->registerInvalidAssociatedFormControl(*this);
</span><span class="cx">     }
</span></span></pre></div>
<a id="trunkSourceWebCorehtmlHTMLFormElementcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/html/HTMLFormElement.cpp (242916 => 242917)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/html/HTMLFormElement.cpp    2019-03-13 23:07:06 UTC (rev 242916)
+++ trunk/Source/WebCore/html/HTMLFormElement.cpp       2019-03-13 23:18:26 UTC (rev 242917)
</span><span class="lines">@@ -704,7 +704,9 @@
</span><span class="cx">         return;
</span><span class="cx">     }
</span><span class="cx"> 
</span><del>-    RefPtr<HTMLFormControlElement> oldDefault = m_defaultButton;
</del><ins>+    ScriptDisallowedScope::InMainThread scriptDisallowedScope;
+
+    auto* oldDefault = m_defaultButton;
</ins><span class="cx">     m_defaultButton = nullptr;
</span><span class="cx">     defaultButton();
</span><span class="cx">     if (m_defaultButton != oldDefault) {
</span></span></pre>
</div>
</div>

</body>
</html>