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authorKees Cook <keescook@chromium.org>2018-05-08 12:52:32 -0700
committerKees Cook <keescook@chromium.org>2018-06-05 12:16:51 -0700
commit49b7f8983aa78581bfd511a26891b26cd734e293 (patch)
treee897c47ee7eacb557d129287451e736cb345ae8d
parentca90800a91ba723d78ded634d037c1d2df8b54d6 (diff)
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>
-rw-r--r--include/linux/slab.h17
1 files changed, 11 insertions, 6 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 81ebd71f8c03..4d759e1ddc33 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -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)