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[PATCH 3/7] malloc/malloc.c: Check for integer overflow in memalign.
- From: Will Newton <will dot newton at linaro dot org>
- To: libc-alpha at sourceware dot org
- Cc: patches at linaro dot org
- Date: Mon, 19 Aug 2013 20:46:56 +0100
- Subject: [PATCH 3/7] malloc/malloc.c: Check for integer overflow in memalign.
A large bytes parameter to memalign could cause an integer overflow
and corrupt allocator internals. Check the overflow does not occur
before continuing with the allocation.
ChangeLog:
2013-08-16 Will Newton <will.newton@linaro.org>
* malloc/malloc.c (__libc_memalign): Check the value of bytes
does not overflow.
---
malloc/malloc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 9aecc85..8c1aab8 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -3015,6 +3015,10 @@ __libc_memalign(size_t alignment, size_t bytes)
/* Otherwise, ensure that it is at least a minimum chunk size */
if (alignment < MINSIZE) alignment = MINSIZE;
+ /* Check for overflow. */
+ if (bytes + alignment + MINSIZE < bytes)
+ return 0;
+
arena_get(ar_ptr, bytes + alignment + MINSIZE);
if(!ar_ptr)
return 0;
--
1.8.1.4