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| author | Kees Cook <keescook@chromium.org> | 2018-05-08 12:52:32 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-06-05 12:16:51 -0700 |
| commit | 49b7f8983aa78581bfd511a26891b26cd734e293 (patch) | |
| tree | e897c47ee7eacb557d129287451e736cb345ae8d | |
| parent | ca90800a91ba723d78ded634d037c1d2df8b54d6 (diff) | |
| download | linux-49b7f8983aa78581bfd511a26891b26cd734e293.tar.bz2 | |
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.h | 17 |
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) |