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authorWill Newton <will.newton@linaro.org>2013-08-16 11:59:37 +0100
committerWill Newton <will.newton@linaro.org>2013-09-11 09:41:04 +0100
commit55e17aadc1ef17a1df9626fb0e9fba290ece3331 (patch)
tree535a0430dd472b5e4059b71b1109312a5d3a59a9
parent1159a193696ad48ec86e5895f6dee3e539619c0e (diff)
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malloc: Check for integer overflow in valloc.
A large bytes parameter to valloc could cause an integer overflow
and corrupt allocator internals. Check the overflow does not occur
before continuing with the allocation.

ChangeLog:

2013-09-11  Will Newton  <will.newton@linaro.org>

	[BZ #15856]
	* malloc/malloc.c (__libc_valloc): Check the value of bytes
	does not overflow.
-rw-r--r--ChangeLog6
-rw-r--r--malloc/malloc.c7
2 files changed, 13 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index b95693f07f..f2d2154714 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2013-09-11  Will Newton  <will.newton@linaro.org>
 
+	[BZ #15856]
+	* malloc/malloc.c (__libc_valloc): Check the value of bytes
+	does not overflow.
+
+2013-09-11  Will Newton  <will.newton@linaro.org>
+
 	[BZ #15855]
 	* malloc/malloc.c (__libc_pvalloc): Check the value of bytes
 	does not overflow.
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 7f43ba3b8f..3148c5f57d 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -3046,6 +3046,13 @@ __libc_valloc(size_t bytes)
 
   size_t pagesz = GLRO(dl_pagesize);
 
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - pagesz - MINSIZE)
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+
   void *(*hook) (size_t, size_t, const void *) =
     force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))