WARNING in close_fs_devices (3)

WARNING in close_fs_devices (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d5beb314 Merge tag 'hyperv-fixes-signed' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1232777d500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7994ac0f2a9b95d9
dashboard link: https://syzkaller.appspot.com/bug?extid=a70e2ad0879f160b9217
compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 8484 at fs/btrfs/volumes.c:1160 close_fs_devices+0x71d/0x7b0 fs/btrfs/volumes.c:1160
Modules linked in:
CPU: 0 PID: 8484 Comm: syz-executor.3 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x71d/0x7b0 fs/btrfs/volumes.c:1160
Code: c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 bb 5b 3f fe 0f 0b e9 6f f9 ff ff e8 af 5b 3f fe 0f 0b e9 3c ff ff ff e8 a3 5b 3f fe <0f> 0b e9 69 ff ff ff 48 c7 c1 24 64 0e 8d 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc900016dfc80 EFLAGS: 00010293
RAX: ffffffff8335c3bd RBX: 0000000000000001 RCX: ffff888015323480
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888024b82108 R08: ffffffff8335c31f R09: ffffed10038cdd27
R10: ffffed10038cdd27 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88801c66e860 R14: 1ffff110038cdd0c R15: 1ffff110038cdd0a
FS:  0000000003329940(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ad0a12280f CR3: 000000006814e000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 btrfs_close_devices+0x8c/0x400 fs/btrfs/volumes.c:1172
 close_ctree+0x5bf/0x6ae fs/btrfs/disk-io.c:4152
 generic_shutdown_super+0x120/0x2a0 fs/super.c:464
 kill_anon_super+0x36/0x60 fs/super.c:1108
 btrfs_kill_super+0x3d/0x50 fs/btrfs/super.c:2263
 deactivate_locked_super+0xa7/0xf0 fs/super.c:335
 cleanup_mnt+0x462/0x510 fs/namespace.c:1118
 task_work_run+0x137/0x1c0 kernel/task_work.c:151
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
 exit_to_user_mode_prepare+0xe4/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x4a/0x170 kernel/entry/common.c:266
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4608e7
Code: 64 89 04 25 d0 02 00 00 58 5f ff d0 48 89 c7 e8 2f be ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe70ea1cb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000004608e7
RDX: 00000000004031f8 RSI: 0000000000000002 RDI: 00007ffe70ea1d60
RBP: 0000000000000538 R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000246 R12: 00007ffe70ea2df0
R13: 000000000332aa60 R14: 0000000000000000 R15: 00007ffe70ea2df0


---
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Re: WARNING in close_fs_devices (3)

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    6174f052 Add linux-next specific files for 20201127
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=141c9553500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=79c69cf2521bef9c
dashboard link: https://syzkaller.appspot.com/bug?extid=a70e2ad0879f160b9217
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11727795500000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1793dcc9500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 8537 at fs/btrfs/volumes.c:1174 close_fs_devices+0x71d/0x930 fs/btrfs/volumes.c:1174
Modules linked in:
CPU: 1 PID: 8537 Comm: syz-executor956 Not tainted 5.10.0-rc5-next-20201127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x71d/0x930 fs/btrfs/volumes.c:1174
Code: e8 88 2f 42 fe 85 db 0f 85 5d f9 ff ff e8 9b 27 42 fe 0f 0b e9 51 f9 ff ff e8 8f 27 42 fe 0f 0b e9 c0 fe ff ff e8 83 27 42 fe <0f> 0b e9 f9 fe ff ff 48 c7 c7 1c 80 ee 8c e8 40 fb 84 fe e9 11 f9
RSP: 0018:ffffc9000183f750 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88801e07b580 RSI: ffffffff832e99dd RDI: 0000000000000003
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffff88801a17b93b
R10: ffffffff832e98d4 R11: 0000000000000000 R12: ffff88801a17b938
R13: ffff88801a17b9f4 R14: ffff888013e1c908 R15: ffff88801a17b850
FS:  00000000025a7880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f674003e048 CR3: 0000000012337000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 btrfs_close_devices+0x8e/0x4b0 fs/btrfs/volumes.c:1186
 open_ctree+0x3f90/0x4035 fs/btrfs/disk-io.c:3484
 btrfs_fill_super fs/btrfs/super.c:1362 [inline]
 btrfs_mount_root.cold+0x14/0x165 fs/btrfs/super.c:1731
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1549
 fc_mount fs/namespace.c:983 [inline]
 vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1013
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1000
 btrfs_mount+0x234/0xa20 fs/btrfs/super.c:1791
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1549
 do_new_mount fs/namespace.c:2896 [inline]
 path_mount+0x12ae/0x1e70 fs/namespace.c:3227
 do_mount fs/namespace.c:3240 [inline]
 __do_sys_mount fs/namespace.c:3448 [inline]
 __se_sys_mount fs/namespace.c:3425 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3425
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4492fa
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 cd a2 fb ff c3 66 2e 0f 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 aa a2 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffe66329388 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004492fa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffe663293d0
RBP: 00007ffe66329410 R08: 00007ffe66329410 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007ffe663293d0 R14: 0000000000000003 R15: 0000000000000005

Re: WARNING in close_fs_devices (3)

[syzbot]

syzbot has bisected this issue to:

commit 4d004099a668c41522242aa146a38cc4eb59cb1e
Author: Peter Zijlstra <peterz@infradead.org>
Date:   Fri Oct 2 09:04:21 2020 +0000

    lockdep: Fix lockdep recursion

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=178c99fd500000
start commit:   6174f052 Add linux-next specific files for 20201127
git tree:       linux-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=144c99fd500000
console output: https://syzkaller.appspot.com/x/log.txt?x=104c99fd500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=79c69cf2521bef9c
dashboard link: https://syzkaller.appspot.com/bug?extid=a70e2ad0879f160b9217
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11727795500000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1793dcc9500000

Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Fixes: 4d004099a668 ("lockdep: Fix lockdep recursion")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection