Changeset 283294 in webkit

Timestamp:

Sep 29, 2021, 7:01:37 PM (5 years ago)

Author:

commit-queue@webkit.org

Message:

Add weakThis check in addition to null check added in r282881
​https://bugs.webkit.org/show_bug.cgi?id=231000
<rdar://83605614>

Patch by Alex Christensen <​achristensen@webkit.org> on 2021-09-29
Reviewed by Brady Eidson.

r282881 made NetworkLoad::start call didCompleteWithError, which can cause the
NetworkResourceLoader to be deleted. It added a null check on m_networkLoad which
sometimes reads freed memory. This certainly isn't great, but luckily we have a way
to check if this object has been deleted. Let's do that.

• NetworkProcess/NetworkResourceLoader.cpp:

(WebKit::NetworkResourceLoader::startNetworkLoad):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• NetworkProcess/NetworkResourceLoader.cpp (modified) (1 diff)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2021-09-29  Alex Christensen  <achristensen@webkit.org>
+
+        Add weakThis check in addition to null check added in r282881
+        https://bugs.webkit.org/show_bug.cgi?id=231000
+        <rdar://83605614>
+
+        Reviewed by Brady Eidson.
+
+        r282881 made NetworkLoad::start call didCompleteWithError, which can cause the
+        NetworkResourceLoader to be deleted.  It added a null check on m_networkLoad which
+        sometimes reads freed memory.  This certainly isn't great, but luckily we have a way
+        to check if this object has been deleted.  Let's do that.
+
+        * NetworkProcess/NetworkResourceLoader.cpp:
+        (WebKit::NetworkResourceLoader::startNetworkLoad):
+
 2021-09-29  Per Arne Vollan <pvollan@apple.com>
 

trunk/Source/WebKit/NetworkProcess/NetworkResourceLoader.cpp

@@ -344 +344 @@
     m_networkLoad = makeUnique<NetworkLoad>(*this, &networkSession->blobRegistry(), WTFMove(parameters), *networkSession);
     
+    auto weakThis = makeWeakPtr(*this);
     if (isSynchronous())
-        m_networkLoad->start();
+        m_networkLoad->start(); // May delete this object
     else
         m_networkLoad->startWithScheduling();
 
-    if (m_networkLoad)
+    if (weakThis && m_networkLoad)
         LOADER_RELEASE_LOG("startNetworkLoad: Going to the network (description=%" PUBLIC_LOG_STRING ")", m_networkLoad->description().utf8().data());
 }