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.
This commit is contained in:
Will Newton 2013-08-12 15:08:02 +01:00
parent c7cabd1355
commit 1159a19369
2 changed files with 13 additions and 0 deletions

View File

@ -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.
2013-09-10 Ondřej Bílka <neleai@seznam.cz>
* sysdeps/ieee754/dbl-64/e_j0.c: Remove DO_NOT_USE_THIS conditionals.

View File

@ -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))