mm: Use overflow helpers in kmalloc_array*()

Instead of open-coded multiplication and bounds checking, use the new
overflow helper.

Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2018-05-08 12:52:32 -07:00
parent ca90800a91
commit 49b7f8983a

View File

@ -13,6 +13,7 @@
#define _LINUX_SLAB_H
#include <linux/gfp.h>
#include <linux/overflow.h>
#include <linux/types.h>
#include <linux/workqueue.h>
@ -624,11 +625,13 @@ int memcg_update_all_caches(int num_memcgs);
*/
static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
{
if (size != 0 && n > SIZE_MAX / size)
size_t bytes;
if (unlikely(check_mul_overflow(n, size, &bytes)))
return NULL;
if (__builtin_constant_p(n) && __builtin_constant_p(size))
return kmalloc(n * size, flags);
return __kmalloc(n * size, flags);
return kmalloc(bytes, flags);
return __kmalloc(bytes, flags);
}
/**
@ -657,11 +660,13 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
int node)
{
if (size != 0 && n > SIZE_MAX / size)
size_t bytes;
if (unlikely(check_mul_overflow(n, size, &bytes)))
return NULL;
if (__builtin_constant_p(n) && __builtin_constant_p(size))
return kmalloc_node(n * size, flags, node);
return __kmalloc_node(n * size, flags, node);
return kmalloc_node(bytes, flags, node);
return __kmalloc_node(bytes, flags, node);
}
static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)