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authorWill Newton <will.newton@linaro.org>2013-08-12 15:08:02 +0100
committerWill Newton <will.newton@linaro.org>2013-09-11 09:39:40 +0100
commit1159a193696ad48ec86e5895f6dee3e539619c0e (patch)
treecfd67498d0e4c6d0a2c12945e28196e8f1c2cfd7 /malloc
parentc7cabd1355e79b7e111904bb3985908cae185b73 (diff)
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malloc: Check for integer overflow in pvalloc.
A large bytes parameter to pvalloc 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 #15855]
	* malloc/malloc.c (__libc_pvalloc): Check the value of bytes
	does not overflow.
Diffstat (limited to 'malloc')
-rw-r--r--malloc/malloc.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c
index dd295f522c..7f43ba3b8f 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -3082,6 +3082,13 @@ __libc_pvalloc(size_t bytes)
   size_t page_mask = GLRO(dl_pagesize) - 1;
   size_t rounded_bytes = (bytes + page_mask) & ~(page_mask);
 
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - 2*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))