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=-7.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 5981BC432C0 for ; Tue, 3 Dec 2019 13:48:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 249052080F for ; Tue, 3 Dec 2019 13:48:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VsFJBHH0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726107AbfLCNso (ORCPT ); Tue, 3 Dec 2019 08:48:44 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:38069 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726628AbfLCNso (ORCPT ); Tue, 3 Dec 2019 08:48:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575380921; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2426TUXH46Dvbw7yzD1hSMTjB99OXECttwgkoFd/DRo=; b=VsFJBHH0VVa/qyNMUtytPY/+epTaxLEVw5/wspYCVVau1GJrGZzTWFJcIaeYWlnht5BVAi ZfESldp1BCcyMDaskzDw/ag3oksqrR1ttVmF7v5SIiEXsO2WZKj279mxF6o0fxXAmSOS/D N/6rOPDJF/st0OP+ATNeaDn8xhOuOJw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-176-dR6Bu5Q8O12bf7__N6_-gQ-1; Tue, 03 Dec 2019 08:48:38 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 55C6E800D41; Tue, 3 Dec 2019 13:48:37 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A51715C28F; Tue, 3 Dec 2019 13:48:36 +0000 (UTC) Date: Tue, 3 Dec 2019 08:48:36 -0500 From: Brian Foster To: syzbot Cc: darrick.wong@oracle.com, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: KASAN: use-after-free Read in xlog_alloc_log (2) Message-ID: <20191203134836.GC18418@bfoster> References: <00000000000087c51905988b297b@google.com> MIME-Version: 1.0 In-Reply-To: <00000000000087c51905988b297b@google.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: dR6Bu5Q8O12bf7__N6_-gQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Nov 29, 2019 at 11:19:08PM -0800, syzbot wrote: > Hello, >=20 > syzbot found the following crash on: >=20 > HEAD commit: 81b6b964 Merge branch 'master' of git://git.kernel.org/pu= b.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=3D13b27696e0000= 0 > kernel config: https://syzkaller.appspot.com/x/.config?x=3D773597fe8d7cb= 41a > dashboard link: https://syzkaller.appspot.com/bug?extid=3Dc732f8644185de3= 40492 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) >=20 > Unfortunately, I don't have any reproducer for this crash yet. >=20 It looks like the out_free_iclog: error path in xlog_alloc_log() doesn't handle the case of a fully initialized iclog list. It uses an iclog !=3D NULL check to terminate the freeing loop, and that might never occur if we failed after the linked list was set up. I've confirmed with a simple error injection test and will send a patch.. Brian > IMPORTANT: if you fix the bug, please add the following tag to the commit= : > Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com >=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > BUG: KASAN: use-after-free in xlog_alloc_log+0x1398/0x14b0 > fs/xfs/xfs_log.c:1495 > Read of size 8 at addr ffff888068139890 by task syz-executor.3/32544 >=20 > CPU: 0 PID: 32544 Comm: syz-executor.3 Not tainted 5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x197/0x210 lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:= 374 > __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:634 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 > xlog_alloc_log+0x1398/0x14b0 fs/xfs/xfs_log.c:1495 > xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:599 > xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:811 > xfs_fs_fill_super+0xd24/0x1750 fs/xfs/xfs_super.c:1732 > mount_bdev+0x304/0x3c0 fs/super.c:1415 > xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1806 > legacy_get_tree+0x108/0x220 fs/fs_context.c:647 > vfs_get_tree+0x8e/0x300 fs/super.c:1545 > do_new_mount fs/namespace.c:2822 [inline] > do_mount+0x135a/0x1b50 fs/namespace.c:3142 > ksys_mount+0xdb/0x150 fs/namespace.c:3351 > __do_sys_mount fs/namespace.c:3365 [inline] > __se_sys_mount fs/namespace.c:3362 [inline] > __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x45d0ca > Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0= f > 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff= ff > 0f 83 2a 8c fb ff c3 66 0f 1f 84 00 00 00 00 00 > RSP: 002b:00007f525b430a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007f525b430b40 RCX: 000000000045d0ca > RDX: 00007f525b430ae0 RSI: 0000000020000100 RDI: 00007f525b430b00 > RBP: 0000000000000001 R08: 00007f525b430b40 R09: 00007f525b430ae0 > R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004 > R13: 00000000004ca258 R14: 00000000004e2870 R15: 00000000ffffffff >=20 > Allocated by task 32544: > save_stack+0x23/0x90 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > __kasan_kmalloc mm/kasan/common.c:510 [inline] > __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524 > __do_kmalloc mm/slab.c:3655 [inline] > __kmalloc+0x163/0x770 mm/slab.c:3664 > kmalloc include/linux/slab.h:561 [inline] > kmem_alloc+0x15b/0x4d0 fs/xfs/kmem.c:21 > kmem_zalloc fs/xfs/kmem.h:68 [inline] > xlog_alloc_log+0xcce/0x14b0 fs/xfs/xfs_log.c:1437 > xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:599 > xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:811 > xfs_fs_fill_super+0xd24/0x1750 fs/xfs/xfs_super.c:1732 > mount_bdev+0x304/0x3c0 fs/super.c:1415 > xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1806 > legacy_get_tree+0x108/0x220 fs/fs_context.c:647 > vfs_get_tree+0x8e/0x300 fs/super.c:1545 > do_new_mount fs/namespace.c:2822 [inline] > do_mount+0x135a/0x1b50 fs/namespace.c:3142 > ksys_mount+0xdb/0x150 fs/namespace.c:3351 > __do_sys_mount fs/namespace.c:3365 [inline] > __se_sys_mount fs/namespace.c:3362 [inline] > __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe >=20 > Freed by task 32544: > save_stack+0x23/0x90 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > kasan_set_free_info mm/kasan/common.c:332 [inline] > __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 > __cache_free mm/slab.c:3425 [inline] > kfree+0x10a/0x2c0 mm/slab.c:3756 > kvfree+0x61/0x70 mm/util.c:593 > kmem_free fs/xfs/kmem.h:61 [inline] > xlog_alloc_log+0xeb5/0x14b0 fs/xfs/xfs_log.c:1497 > xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:599 > xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:811 > xfs_fs_fill_super+0xd24/0x1750 fs/xfs/xfs_super.c:1732 > mount_bdev+0x304/0x3c0 fs/super.c:1415 > xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1806 > legacy_get_tree+0x108/0x220 fs/fs_context.c:647 > vfs_get_tree+0x8e/0x300 fs/super.c:1545 > do_new_mount fs/namespace.c:2822 [inline] > do_mount+0x135a/0x1b50 fs/namespace.c:3142 > ksys_mount+0xdb/0x150 fs/namespace.c:3351 > __do_sys_mount fs/namespace.c:3365 [inline] > __se_sys_mount fs/namespace.c:3362 [inline] > __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe >=20 > The buggy address belongs to the object at ffff888068139800 > which belongs to the cache kmalloc-1k of size 1024 > The buggy address is located 144 bytes inside of > 1024-byte region [ffff888068139800, ffff888068139c00) > The buggy address belongs to the page: > page:ffffea0001a04e40 refcount:1 mapcount:0 mapping:ffff8880aa400c40 > index:0x0 > raw: 00fffe0000000200 ffffea0002728148 ffffea00015604c8 ffff8880aa400c40 > raw: 0000000000000000 ffff888068139000 0000000100000002 0000000000000000 > page dumped because: kasan: bad access detected >=20 > Memory state around the buggy address: > ffff888068139780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff888068139800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff888068139880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff888068139900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff888068139980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 >=20 > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. >=20 > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >=20