From 54e02162d4454a99227f520948bf4494c3d972d0 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Sun, 11 Feb 2018 11:28:12 +0800 Subject: ptr_ring: prevent integer overflow when calculating size Switch to use dividing to prevent integer overflow when size is too big to calculate allocation size properly. Reported-by: Eric Biggers Fixes: 6e6e41c31122 ("ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/ptr_ring.h') diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index b884b7794187..e6335227b844 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -469,7 +469,7 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r, */ static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) { - if (size * sizeof(void *) > KMALLOC_MAX_SIZE) + if (size > KMALLOC_MAX_SIZE / sizeof(void *)) return NULL; return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO); } -- cgit v1.2.3-59-g8ed1b