From kde-commits  Sun Jul 26 03:35:57 2009
From: Kevin Kofler <kevin.kofler () chello ! at>
Date: Sun, 26 Jul 2009 03:35:57 +0000
To: kde-commits
Subject: branches/KDE/4.3/kdelibs/kjs
Message-Id: <1248579357.957322.9209.nullmailer () svn ! kde ! org>
X-MARC-Message: https://marc.info/?l=kde-commits&m=124857936818133

SVN commit 1002473 by kkofler:

Fix integer overflow in KJS JavaScript garbage collector (CVE-2009-1687). Patch adapted from WebKit changeset 41854 by Geoffrey Garen.
FIXME: This will still crash (as in the WebKit commit), so you can still DoS the browser, but at least the overflow is not exploitable anymore.
Backport revision 1002471 from trunk.

 M  +4 -0      collector.cpp  


--- branches/KDE/4.3/kdelibs/kjs/collector.cpp #1002472:1002473
@@ -31,6 +31,7 @@
 #include "value.h"
 
 #include <setjmp.h>
+#include <limits.h>
 #include <algorithm>
 
 #if PLATFORM(DARWIN)
@@ -109,6 +110,9 @@
 
     void append(CollectorBlock* block) {
         if (m_used == m_capacity) {
+            static const size_t maxNumBlocks = ULONG_MAX / sizeof(CollectorBlock*) / GROWTH_FACTOR;
+            if (m_capacity > maxNumBlocks)
+                CRASH();
             m_capacity = max(MIN_ARRAY_SIZE, m_capacity * GROWTH_FACTOR);
             m_data = static_cast<CollectorBlock **>(fastRealloc(m_data, m_capacity * sizeof(CollectorBlock *)));
         }