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INFO: task hung in mount_bdev (3)

Status: upstream: reported C repro on 2020/12/19 04:11
Reported-by: syzbot+4b0dd68b46b492efbd33@syzkaller.appspotmail.com
First crash: 1434d, last: 635d
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in mount_bdev 1 1839d 1839d 0/1 auto-closed as invalid on 2020/03/08 13:23
upstream INFO: task hung in mount_bdev isofs 1 2170d 2169d 0/28 closed as dup on 2018/12/14 15:35
linux-4.14 INFO: task hung in mount_bdev (2) 1 1701d 1701d 0/1 auto-closed as invalid on 2020/07/24 15:46
upstream INFO: task hung in mount_bdev (2) udf ext4 C done 1 2034d 2030d 0/28 closed as dup on 2019/05/03 10:52
linux-4.19 INFO: task hung in mount_bdev C error 3 1143d 1919d 0/1 upstream: reported C repro on 2019/08/22 06:31
▶ ▼ Fix bisection attempts (25)
Created Duration User Patch Repo Result
2023/02/25 22:19 33m bisect fix linux-4.14.y OK (0) job log log
2023/01/25 13:16 27m bisect fix linux-4.14.y OK (0) job log log
2022/11/14 09:04 30m bisect fix linux-4.14.y OK (0) job log log
2022/10/14 23:20 27m bisect fix linux-4.14.y OK (0) job log log
2022/09/14 03:52 24m bisect fix linux-4.14.y OK (0) job log log
2022/08/15 03:25 27m bisect fix linux-4.14.y OK (0) job log log
2022/07/16 02:54 30m bisect fix linux-4.14.y OK (0) job log log
2022/06/16 02:15 38m bisect fix linux-4.14.y OK (0) job log log
2022/05/17 01:45 28m bisect fix linux-4.14.y OK (0) job log log
2022/04/17 01:17 28m bisect fix linux-4.14.y OK (0) job log log
2022/03/16 10:41 26m bisect fix linux-4.14.y OK (0) job log log
2022/02/14 10:06 35m bisect fix linux-4.14.y OK (0) job log log
2022/01/15 09:11 34m bisect fix linux-4.14.y OK (0) job log log
2021/12/16 08:42 28m bisect fix linux-4.14.y OK (0) job log log
2021/11/16 08:15 26m bisect fix linux-4.14.y OK (0) job log log
2021/10/17 07:45 29m bisect fix linux-4.14.y OK (0) job log log
2021/09/17 07:18 27m bisect fix linux-4.14.y OK (0) job log log
2021/08/18 06:46 31m bisect fix linux-4.14.y OK (0) job log log
2021/07/19 06:18 28m bisect fix linux-4.14.y OK (0) job log log
2021/06/19 05:49 27m bisect fix linux-4.14.y OK (0) job log log
2021/05/04 09:28 32m bisect fix linux-4.14.y OK (0) job log log
2021/03/25 14:02 31m bisect fix linux-4.14.y OK (0) job log log
2021/02/23 11:44 31m bisect fix linux-4.14.y OK (0) job log log
2021/02/19 07:41 18m bisect fix linux-4.14.y error job log
2021/01/18 04:10 32m bisect fix linux-4.14.y OK (0) job log log

Sample crash report:
UDF-fs: error (device loop3): udf_read_tagged: read failed, block=512, location=512
UDF-fs: warning (device loop3): udf_load_vrs: No anchor found
UDF-fs: Scanning with blocksize 512 failed
print_req_error: I/O error, dev loop3, sector 64
INFO: task syz-executor165:7996 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  7996   7986 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60bab12208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb408 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb40c
R13: 00007ffdbdfa017f R14: 00007f60bab12300 R15: 0000000000022000
INFO: task syz-executor165:8032 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8032   7986 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60baad0208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c
R13: 00007ffdbdfa017f R14: 00007f60baad0300 R15: 0000000000022000
INFO: task syz-executor165:7991 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  7991   7984 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:56
 grab_super+0x55/0x140 fs/super.c:373
 sget_userns+0x2b1/0xc10 fs/super.c:504
 sget+0xd1/0x110 fs/super.c:572
 mount_bdev+0xcd/0x360 fs/super.c:1107
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60bab12208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb408 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb40c
R13: 00007ffdbdfa017f R14: 00007f60bab12300 R15: 0000000000022000
INFO: task syz-executor165:8029 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8029   7984 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60baad0208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c
R13: 00007ffdbdfa017f R14: 00007f60baad0300 R15: 0000000000022000
INFO: task syz-executor165:8028 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8028   7982 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60baad0208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c
R13: 00007ffdbdfa017f R14: 00007f60baad0300 R15: 0000000000022000
INFO: task syz-executor165:8000 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8000   7981 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60bab12208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb408 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb40c
R13: 00007ffdbdfa017f R14: 00007f60bab12300 R15: 0000000000022000
INFO: task syz-executor165:8033 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8033   7981 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60baad0208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c
R13: 00007ffdbdfa017f R14: 00007f60baad0300 R15: 0000000000022000
INFO: task syz-executor165:7998 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  7998   7985 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60bab12208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb408 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb40c
R13: 00007ffdbdfa017f R14: 00007f60bab12300 R15: 0000000000022000
INFO: task syz-executor165:8030 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  8030   7985 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60baad0208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c
R13: 00007ffdbdfa017f R14: 00007f60baad0300 R15: 0000000000022000
INFO: task syz-executor165:7999 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor165 D29920  7999   7983 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
 mount_bdev+0x71/0x360 fs/super.c:1101
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0xe53/0x2a00 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x44a689
RSP: 002b:00007f60bab12208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb408 RCX: 000000000044a689
RDX: 0000000020000040 RSI: 0000000020000280 RDI: 00000000200004c0
RBP: 00000000004cb400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb40c
R13: 00007ffdbdfa017f R14: 00007f60bab12300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1534:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8700b7b7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by syz-executor165/7996:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8032:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
2 locks held by syz-executor165/7991:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
 #1:  (&type->s_umount_key#47){+.+.}, at: [<ffffffff818737e5>] grab_super+0x55/0x140 fs/super.c:373
1 lock held by syz-executor165/8029:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8028:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8000:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8033:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/7998:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8030:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/7999:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101
1 lock held by syz-executor165/8031:
 #0:  (&bdev->bd_fsfreeze_mutex){+.+.}, at: [<ffffffff81874751>] mount_bdev+0x71/0x360 fs/super.c:1101

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5b9/0xb40 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4622 Comm: systemd-journal Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a17c80c0 task.stack: ffff8880a17d0000
RIP: 0010:prepare_creds+0x175/0x490 kernel/cred.c:269
RSP: 0018:ffff8880a17d7e38 EFLAGS: 00000202
RAX: ffffffff88f44e40 RBX: ffff8880a17c80c0 RCX: 0000000000000000
RDX: 1ffff110156d4632 RSI: ffff8880a1db76b8 RDI: ffff8880ab6a3190
RBP: ffff8880a1db7600 R08: 0000000000000001 R09: ffffed10156d4636
R10: ffff8880ab6a31b7 R11: 0000000000000000 R12: ffff8880ab6a3100
R13: ffff8880a17d7fd0 R14: 00000000ffffff9c R15: 000055cb89f379a3
FS:  00007f0e3533d8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0e3272b018 CR3: 00000000a1053000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 SYSC_faccessat fs/open.c:365 [inline]
 SyS_faccessat+0x7b/0x680 fs/open.c:353
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f0e345f89c7
RSP: 002b:00007ffd8cc04908 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffd8cc07930 RCX: 00007f0e345f89c7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055cb89f379a3
RBP: 00007ffd8cc04a50 R08: 000055cb89f2d3e5 R09: 0000000000000018
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055cb8a0ff8a0 R15: 00007ffd8cc04f40
Code: 24 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b3 02 00 00 49 8b 84 24 90 00 00 00 f0 ff 00 <49> 8d bc 24 98 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/05/20 05:04 linux-4.14.y 7d7d1c0ab3eb a343ba6b .config console log report syz C ci2-linux-4-14 INFO: task hung in mount_bdev
2021/05/09 22:45 linux-4.14.y 7d7d1c0ab3eb bc5434be .config console log report syz C ci2-linux-4-14 INFO: task hung in mount_bdev
2021/01/19 15:52 linux-4.14.y 2762b48e9611 63631df1 .config console log report syz C ci2-linux-4-14 INFO: task hung in mount_bdev
2020/12/19 04:10 linux-4.14.y 3f2ecb86cb90 04201c06 .config console log report syz C ci2-linux-4-14
2021/04/04 09:26 linux-4.14.y bd634aa64163 6a81331a .config console log report info ci2-linux-4-14 INFO: task hung in mount_bdev
* Struck through repros no longer work on HEAD.