From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38664C43331 for ; Thu, 26 Mar 2020 11:21:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CDE3820714 for ; Thu, 26 Mar 2020 11:21:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDE3820714 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6442D6B007D; Thu, 26 Mar 2020 07:21:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F4206B0080; Thu, 26 Mar 2020 07:21:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 514CB6B007D; Thu, 26 Mar 2020 07:21:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 366166B007D for ; Thu, 26 Mar 2020 07:21:11 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 1E0D2180AD806 for ; Thu, 26 Mar 2020 11:21:11 +0000 (UTC) X-FDA: 76637271942.02.name49_618add9737248 X-HE-Tag: name49_618add9737248 X-Filterd-Recvd-Size: 2776 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Thu, 26 Mar 2020 11:21:09 +0000 (UTC) Received: from fsav101.sakura.ne.jp (fsav101.sakura.ne.jp [27.133.134.228]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 02QBL2g7030582; Thu, 26 Mar 2020 20:21:02 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav101.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav101.sakura.ne.jp); Thu, 26 Mar 2020 20:21:02 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav101.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 02QBL28d030578 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 26 Mar 2020 20:21:02 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: Re: kernel panic: stack is corrupted in mpol_to_str To: syzbot References: <000000000000276fa005a1b8aeb5@google.com> Cc: linux-mm@kvack.org, syzkaller-bugs@googlegroups.com From: Tetsuo Handa Message-ID: <56f09db2-7e46-74b5-09c3-4873b3acc56c@I-love.SAKURA.ne.jp> Date: Thu, 26 Mar 2020 20:21:00 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <000000000000276fa005a1b8aeb5@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000026, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Two reproducers have only offset difference. 1c1 < // https://syzkaller.appspot.com/bug?id=95622e9b1d82dd9e1368d04b2d11f9daa102b685 --- > // https://syzkaller.appspot.com/bug?id=b642faac21312365cd30cc83ec73b2a05f73bf8a 134,142c134,142 < memcpy((void*)0x20000000, "tmpfs\000", 6); < memcpy((void*)0x20002140, "./file0\000", 8); < memcpy((void*)0x200000c0, "mpol", 4); < *(uint8_t*)0x200000c4 = 0x3d; < memcpy((void*)0x200000c5, "prefer", 6); < *(uint8_t*)0x200000cb = 0x3a; < *(uint8_t*)0x200000cc = 0x2c; < *(uint8_t*)0x200000cd = 0; < syz_mount_image(0x20000000, 0x20002140, 0, 0, 0, 0, 0x200000c0); --- > memcpy((void*)0x200000c0, "tmpfs\000", 6); > memcpy((void*)0x20000000, "./file0\000", 8); > memcpy((void*)0x20000100, "mpol", 4); > *(uint8_t*)0x20000104 = 0x3d; > memcpy((void*)0x20000105, "prefer", 6); > *(uint8_t*)0x2000010b = 0x3a; > *(uint8_t*)0x2000010c = 0x2c; > *(uint8_t*)0x2000010d = 0; > syz_mount_image(0x200000c0, 0x20000000, 0, 0, 0, 0, 0x20000100); #syz dup: KASAN: stack-out-of-bounds Write in mpol_to_str