From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f199.google.com (mail-io0-f199.google.com [209.85.223.199]) by kanga.kvack.org (Postfix) with ESMTP id 1D0236B0005 for ; Tue, 31 May 2016 07:52:09 -0400 (EDT) Received: by mail-io0-f199.google.com with SMTP id h5so33216722ioh.1 for ; Tue, 31 May 2016 04:52:09 -0700 (PDT) Received: from emea01-am1-obe.outbound.protection.outlook.com (mail-am1on0108.outbound.protection.outlook.com. [157.56.112.108]) by mx.google.com with ESMTPS id n3si2210603oia.131.2016.05.31.04.52.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 31 May 2016 04:52:07 -0700 (PDT) Subject: Re: [PATCH] mm, kasan: introduce a special shadow value for allocator metadata References: <1464691466-59010-1-git-send-email-glider@google.com> From: Andrey Ryabinin Message-ID: <574D7B11.8090709@virtuozzo.com> Date: Tue, 31 May 2016 14:52:49 +0300 MIME-Version: 1.0 In-Reply-To: <1464691466-59010-1-git-send-email-glider@google.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Alexander Potapenko , adech.fo@gmail.com, cl@linux.com, dvyukov@google.com, akpm@linux-foundation.org, rostedt@goodmis.org, iamjoonsoo.kim@lge.com, js1304@gmail.com, kcc@google.com Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 05/31/2016 01:44 PM, Alexander Potapenko wrote: > Add a special shadow value to distinguish accesses to KASAN-specific > allocator metadata. > > Unlike AddressSanitizer in the userspace, KASAN lets the kernel proceed > after a memory error. However a write to the kmalloc metadata may cause > memory corruptions that will make the tool itself unreliable and induce > crashes later on. Warning about such corruptions will ease the > debugging. It will not. Whether out-of-bounds hits metadata or not is absolutely irrelevant to the bug itself. This information doesn't help to understand, analyze or fix the bug. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org