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authorWill Newton <will.newton@linaro.org>2013-08-12 15:08:02 +0100
committerAllan McRae <allan@archlinux.org>2013-10-25 23:53:17 +1000
commit63e9a36056fe53621fa3001fe22b4833a9ea9457 (patch)
tree8855abbfa7b15d8d0161c90b57563e30137e9bd0
parenta3ed3a127ca30b3b25aab0b441f9f3f0ecc07f7e (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.

(cherry picked from commit 1159a193696ad48ec86e5895f6dee3e539619c0e)
-rw-r--r--ChangeLog6
-rw-r--r--malloc/malloc.c7
2 files changed, 13 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 7fae731ba8..0c9e743a6b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-09-11  Will Newton  <will.newton@linaro.org>
+
+	[BZ #15855]
+	* malloc/malloc.c (__libc_pvalloc): Check the value of bytes
+	does not overflow.
+
 2013-08-16  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #14699]
diff --git a/malloc/malloc.c b/malloc/malloc.c
index be472b2ba3..bcc08c45f7 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))