INFO: task syz-executor:5840 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:19552 pid:5840  tgid:5840  ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5373 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6760
 __schedule_loop kernel/sched/core.c:6837 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6852
 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 kthread_stop+0x1a1/0x640 kernel/kthread.c:791
 bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:414
 __bch2_fs_read_only+0x47/0x450 fs/bcachefs/super.c:265
 bch2_fs_read_only+0xc3c/0x1340 fs/bcachefs/super.c:356
 __bch2_fs_stop+0x105/0x5c0 fs/bcachefs/super.c:634
 generic_shutdown_super+0x139/0x2d0 fs/super.c:642
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2312
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1424
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92f8b8e497
RSP: 002b:00007fff79c5ad38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f92f8c0e08c RCX: 00007f92f8b8e497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff79c5adf0
RBP: 00007fff79c5adf0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff79c5be80
R13: 00007f92f8c0e08c R14: 000000000007634e R15: 00007fff79c5bec0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/8:
 #0: ffff888144abc148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888144abc148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900000d7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000d7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffff888028bca190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #2: ffff888028bca190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861
1 lock held by khungtaskd/30:
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by kworker/u8:6/1104:
2 locks held by getty/5587:
 #0: ffff8880318660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5840:
 #0: ffff88803627a0e0 (&type->s_umount_key#92){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88803627a0e0 (&type->s_umount_key#92){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88803627a0e0 (&type->s_umount_key#92){+.+.}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
 #1: ffff888057100278 (&c->state_lock){+.+.}-{4:4}, at: __bch2_fs_stop+0xfd/0x5c0 fs/bcachefs/super.c:633
3 locks held by kworker/1:7/6731:
3 locks held by kworker/u8:16/9592:
1 lock held by syz.5.1128/9999:
 #0: ffff88804a7900e0 (&type->s_umount_key#55/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344
2 locks held by dhcpcd/10023:
 #0: ffff888078864258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1625 [inline]
 #0: ffff888078864258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcb0 net/packet/af_packet.c:3253
 #1: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #1: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:998

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9999 Comm: syz.5.1128 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline]
RIP: 0010:preempt_count_sub+0x5d/0x170 kernel/sched/core.c:5890
Code: 22 65 8b 05 ad 1c 74 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 27 81 fb fe 00 00 00 77 07 0f b6 c0 85 c0 74 5f 65 8b 05 8b 1c 74 7e <f7> db 65 01 1d 82 1c 74 7e 5b 41 5e c3 cc cc cc cc 90 e8 3c f2 64
RSP: 0000:ffffc9000bd07140 EFLAGS: 00000006
RAX: 0000000080000003 RBX: 0000000000000001 RCX: 0000000000000003
RDX: 000000000000014d RSI: ffffffff8c8156c0 RDI: 0000000000000001
RBP: 0000000000000021 R08: ffffffff85871c95 R09: 1ffff11004a41046
R10: dffffc0000000000 R11: ffffffff8c0c36b0 R12: 0000000000000020
R13: 1ffffffff3536fee R14: dffffc0000000000 R15: 0000000000000001
FS:  00007f584269b6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5fda066880 CR3: 00000000291e8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 delay_tsc+0x4f/0xe0 arch/x86/lib/delay.c:77
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x169/0x320 drivers/tty/serial/8250/8250_port.c:2106
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline]
 serial8250_console_write+0x134c/0x1e00 drivers/tty/serial/8250/8250_port.c:3465
 console_emit_next_record kernel/printk/printk.c:3122 [inline]
 console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210
 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
 console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
 _printk+0xd5/0x120 kernel/printk/printk.c:2457
 __xfs_printk fs/xfs/xfs_message.c:24 [inline]
 xfs_printk_level+0x1ca/0x320 fs/xfs/xfs_message.c:44
 xfs_log_mount_finish+0x251/0x360 fs/xfs/xfs_log.c:766
 xfs_mountfs+0x1cd7/0x2500 fs/xfs/xfs_mount.c:1018
 xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
 get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2be/0xb40 fs/namespace.c:3659
 do_mount fs/namespace.c:3999 [inline]
 __do_sys_mount fs/namespace.c:4210 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4187
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f584178e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f584269ae68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f584269aef0 RCX: 00007f584178e90a
RDX: 0000400000000240 RSI: 0000400000009640 RDI: 00007f584269aeb0
RBP: 0000400000000240 R08: 00007f584269aef0 R09: 0000000000200800
R10: 0000000000200800 R11: 0000000000000246 R12: 0000400000009640
R13: 00007f584269aeb0 R14: 0000000000009606 R15: 00004000000002c0
 </TASK>