From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932391AbcG1Pbr (ORCPT ); Thu, 28 Jul 2016 11:31:47 -0400 Received: from mail-wm0-f41.google.com ([74.125.82.41]:35484 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758873AbcG1Pbb (ORCPT ); Thu, 28 Jul 2016 11:31:31 -0400 From: Alexander Potapenko To: dvyukov@google.com, kcc@google.com, aryabinin@virtuozzo.com, adech.fo@gmail.com, cl@linux.com, akpm@linux-foundation.org, rostedt@goodmis.org, js1304@gmail.com, iamjoonsoo.kim@lge.com, kuthonuzo.luruo@hpe.com Cc: kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v8 2/3] mm, kasan: align free_meta_offset on sizeof(void*) Date: Thu, 28 Jul 2016 17:31:18 +0200 Message-Id: <1469719879-11761-3-git-send-email-glider@google.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: <1469719879-11761-1-git-send-email-glider@google.com> References: <1469719879-11761-1-git-send-email-glider@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When free_meta_offset is not zero, it is usually aligned on 4 bytes, because the size of preceding kasan_alloc_meta is aligned on 4 bytes. As a result, accesses to kasan_free_meta fields may be misaligned. Signed-off-by: Alexander Potapenko --- mm/kasan/kasan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 6845f92..0379551 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -390,7 +390,8 @@ void kasan_cache_create(struct kmem_cache *cache, size_t *size, /* Add free meta. */ if (cache->flags & SLAB_DESTROY_BY_RCU || cache->ctor || cache->object_size < sizeof(struct kasan_free_meta)) { - cache->kasan_info.free_meta_offset = *size; + cache->kasan_info.free_meta_offset = + ALIGN(*size, sizeof(void *)); *size += sizeof(struct kasan_free_meta); } redzone_adjust = optimal_redzone(cache->object_size) - -- 2.8.0.rc3.226.g39d4020