From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net] ptr_ring: prevent integer overflow when calculating size Date: Sun, 11 Feb 2018 11:28:12 +0800 Message-ID: <1518319692-5421-1-git-send-email-jasowang@redhat.com> Cc: mst@redhat.com, ebiggers3@gmail.com, Jason Wang To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58672 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751921AbeBKD2R (ORCPT ); Sat, 10 Feb 2018 22:28:17 -0500 Sender: netdev-owner@vger.kernel.org List-ID: 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 --- include/linux/ptr_ring.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index b884b77..e633522 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); } -- 2.7.4