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=-3.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 5526CC4338F for ; Tue, 24 Aug 2021 18:19:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3731B61212 for ; Tue, 24 Aug 2021 18:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233327AbhHXSUG (ORCPT ); Tue, 24 Aug 2021 14:20:06 -0400 Received: from mail-io1-f70.google.com ([209.85.166.70]:48855 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233045AbhHXSUF (ORCPT ); Tue, 24 Aug 2021 14:20:05 -0400 Received: by mail-io1-f70.google.com with SMTP id d12-20020a6b680c000000b005b86e36a1f4so12817978ioc.15 for ; Tue, 24 Aug 2021 11:19:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=hgW0R3Cqypzh/PaKnkXmkgTVIsdRWlaPqbcdFnM1yf4=; b=cgFgF6kW9ZAO8fVff6Cqx3W2xb8RgjwMnxs8Ied2qJNyQhwwfD4um0LSkbOMnKDU/r eRsGe7oeo7Dat4f0KXzp4ZBADFDooDD4ZG81HlGZ12n9ssOQwLZ06iEBRCVPaJPdB8E3 Xf+bix0cp7GVt9fD2fuwJlc2t44Dz78MA8AHDMKxHVZ7C+VxowkAPDvGwlpD2BxMNn+p J9A6T6XkRsWxnF6YXweRy2CCTInURjMfaD9IIQ/HJYgj6duA0dVVJidbhJAP7kVk6l1i yDoibAzzcSX/SSsr8imyLTa1+gUWsAx+XW5RWLwbdgYPp0GLluxjy5PCxQ4xx6vSwSrx cOEQ== X-Gm-Message-State: AOAM530/sr0+XVdJCg8TBuXbqfANyfwAgzXjeIl/Mfb7ctQCLpEqwZu6 qoXPQQ+KA5gkSKIcbr19CnO9cukX0If0rh72EcV5IAEID5j6 X-Google-Smtp-Source: ABdhPJwEaTZEC/DTrCc5eemqt08KwYR9CjP3i4ycabjWdTeMxIiZUgASqsLlkpoBDLHwmm/1fGD6AXEdFEowjijLkqsY8VSeTM8R MIME-Version: 1.0 X-Received: by 2002:a5e:a813:: with SMTP id c19mr32512644ioa.199.1629829161333; Tue, 24 Aug 2021 11:19:21 -0700 (PDT) Date: Tue, 24 Aug 2021 11:19:21 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000034b9ee05ca522caa@google.com> Subject: [syzbot] possible deadlock in md_open From: syzbot To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, song@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: 372b2891c15a Add linux-next specific files for 20210824 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=124dca75300000 kernel config: https://syzkaller.appspot.com/x/.config?x=18ce42745c8b0dd6 dashboard link: https://syzkaller.appspot.com/bug?extid=fadc0aaf497e6a493b9f compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13b10d05300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13fa60fe300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc7-next-20210824-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor325/6558 is trying to acquire lock: ffff888013f90230 (&mddev->open_mutex){+.+.}-{3:3}, at: md_open+0xfd/0x2e0 drivers/md/md.c:7815 but task is already holding lock: ffff888077ce3118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 fs/block_dev.c:1227 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 bd_register_pending_holders+0x2c/0x470 block/holder.c:160 device_add_disk+0x75e/0xfd0 block/genhd.c:505 add_disk include/linux/genhd.h:221 [inline] md_alloc+0x91d/0x1150 drivers/md/md.c:5707 md_probe+0x69/0x70 drivers/md/md.c:5738 blk_request_module+0x111/0x1d0 block/genhd.c:667 blkdev_get_no_open+0x178/0x1e0 fs/block_dev.c:1150 blkdev_get_by_dev.part.0+0x22/0xb60 fs/block_dev.c:1214 blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267 swsusp_check+0x4d/0x270 kernel/power/swap.c:1525 software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977 software_resume kernel/power/hibernate.c:86 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1179 kobj_attr_store+0x50/0x80 lib/kobject.c:856 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:511 vfs_write+0x7cf/0xae0 fs/read_write.c:598 ksys_write+0x12d/0x250 fs/read_write.c:651 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&mddev->open_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 md_open+0xfd/0x2e0 drivers/md/md.c:7815 blkdev_get_whole+0x99/0x2a0 fs/block_dev.c:1079 blkdev_get_by_dev.part.0+0x354/0xb60 fs/block_dev.c:1234 blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267 swsusp_check+0x4d/0x270 kernel/power/swap.c:1525 software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977 software_resume kernel/power/hibernate.c:86 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1179 kobj_attr_store+0x50/0x80 lib/kobject.c:856 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:511 vfs_write+0x7cf/0xae0 fs/read_write.c:598 ksys_write+0x12d/0x250 fs/read_write.c:651 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&disk->open_mutex); lock(&mddev->open_mutex); lock(&disk->open_mutex); lock(&mddev->open_mutex); *** DEADLOCK *** 5 locks held by syz-executor325/6558: #0: ffff88807f6bc460 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:651 #1: ffff88801a6a3488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x287/0x500 fs/kernfs/file.c:287 #2: ffff8881441a6830 (kn->active#90){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ab/0x500 fs/kernfs/file.c:288 #3: ffffffff8b84fc68 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume.part.0+0x19/0x1f0 kernel/power/hibernate.c:932 #4: ffff888077ce3118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb60 fs/block_dev.c:1227 stack backtrace: CPU: 1 PID: 6558 Comm: syz-executor325 Not tainted 5.14.0-rc7-next-20210824-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __mutex_lock_common kernel/locking/mutex.c:596 [inline] __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729 md_open+0xfd/0x2e0 drivers/md/md.c:7815 blkdev_get_whole+0x99/0x2a0 fs/block_dev.c:1079 blkdev_get_by_dev.part.0+0x354/0xb60 fs/block_dev.c:1234 blkdev_get_by_dev+0x6b/0x80 fs/block_dev.c:1267 swsusp_check+0x4d/0x270 kernel/power/swap.c:1525 software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:977 software_resume kernel/power/hibernate.c:86 [inline] resume_store+0x161/0x190 kernel/power/hibernate.c:1179 kobj_attr_store+0x50/0x80 lib/kobject.c:856 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x429/0x660 fs/read_write.c:511 vfs_write+0x7cf/0xae0 fs/read_write.c:598 ksys_write+0x12d/0x250 fs/read_write.c:651 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43f0e9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd59408358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043f0e9 RDX: 000000000000fdef RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000402e40 R08: 0000000000000012 R09: 0000000000400488 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402ed0 R13: 0000000000000000 R14: 00000000004ad018 R15: 0000000000400488 --- This report 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. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches