mm: Use overflow helpers in kvmalloc()

Instead of open-coded multiplication and bounds checking, use the new
overflow helper. Additionally prepare for vmalloc() users to add
array_size()-family helpers in the future.

Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2018-05-08 12:55:26 -07:00
parent 49b7f8983a
commit 3b3b1a29eb
2 changed files with 6 additions and 2 deletions

View file

@ -25,6 +25,7 @@
#include <linux/err.h>
#include <linux/page_ref.h>
#include <linux/memremap.h>
#include <linux/overflow.h>
struct mempolicy;
struct anon_vma;
@ -560,10 +561,12 @@ static inline void *kvzalloc(size_t size, gfp_t flags)
static inline void *kvmalloc_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;
return kvmalloc(n * size, flags);
return kvmalloc(bytes, flags);
}
extern void kvfree(const void *addr);

View file

@ -8,6 +8,7 @@
#include <linux/llist.h>
#include <asm/page.h> /* pgprot_t */
#include <linux/rbtree.h>
#include <linux/overflow.h>
struct vm_area_struct; /* vma defining user mapping in mm_types.h */
struct notifier_block; /* in notifier.h */