From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755888AbcHVOGu (ORCPT ); Mon, 22 Aug 2016 10:06:50 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:40442 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755640AbcHVOGp (ORCPT ); Mon, 22 Aug 2016 10:06:45 -0400 Subject: Re: [PATCH] bdev: fix NULL pointer dereference To: Vegard Nossum References: <20160822104743.16077-1-vegard.nossum@oracle.com> CC: , , Shaohua Li , Tejun Heo , From: Jens Axboe Message-ID: <858239cb-4b97-c071-2317-7e6da11675ac@fb.com> Date: Mon, 22 Aug 2016 08:06:32 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160822104743.16077-1-vegard.nossum@oracle.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [216.160.245.98] X-ClientProxiedBy: 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1;CY4PR15MB1192;20:Ezjg3kM2+E++GzToQy/e9G5NR/4m2jkgoJ6OGmxb4EKwzIr80X9abQhjSvh/MsbO25zU3AWKWRFjg8yd79Se0y9uG8JjgXu/IpCOM865Rw4Nv/jf1PSKzrmh5k3V8EoAqsf99hjOv7trxpZlUitWuGmRTPMdCLNeljDV8E5b4nQ= X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Aug 2016 14:06:35.5740 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR15MB1192 X-OriginatorOrg: fb.com X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-08-22_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/22/2016 04:47 AM, Vegard Nossum wrote: > I got this: > > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] PREEMPT SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > CPU: 0 PID: 5505 Comm: syz-executor Not tainted 4.8.0-rc2+ #161 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 > task: ffff880113415940 task.stack: ffff880118350000 > RIP: 0010:[] [] bd_mount+0x52/0xa0 > RSP: 0018:ffff880118357ca0 EFLAGS: 00010207 > RAX: dffffc0000000000 RBX: ffffffffffffffff RCX: ffffc90000bb6000 > RDX: 0000000000000018 RSI: ffffffff846d6b20 RDI: 00000000000000c7 > RBP: ffff880118357cb0 R08: ffff880115967c68 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801188211e8 > R13: ffffffff847baa20 R14: ffff8801139cb000 R15: 0000000000000080 > FS: 00007fa3ff6c0700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fc1d8cc7e78 CR3: 0000000109f20000 CR4: 00000000000006f0 > DR0: 000000000000001e DR1: 000000000000001e DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > Stack: > ffff880112cfd6c0 ffff8801188211e8 ffff880118357cf0 ffffffff8167f207 > ffffffff816d7a1e ffff880112a413c0 ffffffff847baa20 ffff8801188211e8 > 0000000000000080 ffff880112cfd6c0 ffff880118357d38 ffffffff816dce0a > Call Trace: > [] mount_fs+0x97/0x2e0 > [] ? alloc_vfsmnt+0x55e/0x760 > [] vfs_kern_mount+0x7a/0x300 > [] ? _raw_read_unlock+0x2c/0x50 > [] do_mount+0x3d7/0x2730 > [] ? trace_do_page_fault+0x1f4/0x3a0 > [] ? copy_mount_string+0x40/0x40 > [] ? memset+0x31/0x40 > [] ? copy_mount_options+0x1ee/0x320 > [] SyS_mount+0xb2/0x120 > [] ? copy_mnt_ns+0x970/0x970 > [] do_syscall_64+0x1c4/0x4e0 > [] entry_SYSCALL64_slow_path+0x25/0x25 > Code: 83 e8 63 1b fc ff 48 85 c0 48 89 c3 74 4c e8 56 35 d1 ff 48 8d bb c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 36 4c 8b a3 c8 00 00 00 48 b8 00 00 00 00 00 fc > RIP [] bd_mount+0x52/0xa0 > RSP > ---[ end trace 13690ad962168b98 ]--- > > mount_pseudo() returns ERR_PTR(), not NULL, on error. Thanks, applied. -- Jens Axboe