INFO: task syz.3.893:7744 blocked for more than 144 seconds.
      Not tainted 5.15.180-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.893       state:D stack:26432 pid: 7744 ppid:  4176 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xac/0x1e0 fs/super.c:716
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f20dfb44169
RSP: 002b:00007f20dd96a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f20dfd6c160 RCX: 00007f20dfb44169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f20dfd6c160 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f20dfd6c160 R15: 00007ffca5c0a448
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1f560 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by dhcpcd/3836:
 #0: ffffffff8dc44148 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8dc44148 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x956/0xef0 net/core/rtnetlink.c:5647
2 locks held by getty/3929:
 #0: ffff88814cca6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by syz-executor/4171:
 #0: ffff888020abfd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:915
 #1: ffff888020c98468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365
2 locks held by kworker/0:18/4335:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000318fd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
4 locks held by syz-executor/5824:
1 lock held by syz-executor/6346:
 #0: ffff888077fe40e0 (&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
1 lock held by syz.3.893/7744:
 #0: ffff888077fe40e0 (&type->s_umount_key#53){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
1 lock held by syz-executor/8718:
 #0: ffffffff8cb23b28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #0: ffffffff8cb23b28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845
2 locks held by syz.8.1316/9529:
 #0: ffffffff8dc44148 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8dc44148 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x956/0xef0 net/core/rtnetlink.c:5647
 #1: ffffffff8cb23b28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #1: ffffffff8cb23b28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.180-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:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:369
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5824 Comm: syz-executor Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:visit_lock_entry kernel/locking/lockdep.c:1481 [inline]
RIP: 0010:__bfs kernel/locking/lockdep.c:1761 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1805 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2745 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3057 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3172 [inline]
RIP: 0010:validate_chain+0x1d05/0x5930 kernel/locking/lockdep.c:3788
Code: 41 b5 01 eb 0c 4d 8b 3f 4d 39 f7 0f 84 e3 fb ff ff 49 8d 5f 30 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 81 d7 66 00 4c 89 23 41 f6 c5 01 0f 84 82 00 00
RSP: 0018:ffffc900031aef60 EFLAGS: 00000046
RAX: 1ffffffff267cd5b RBX: ffffffff933e6ad8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90359c50
RBP: ffffc900031af210 R08: dffffc0000000000 R09: fffffbfff2132219
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff932d0fd8
R13: 0000000000000000 R14: ffffffff90359c30 R15: ffffffff933e6aa8
FS:  000055555c1a6500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d8967621e8 CR3: 000000006469e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 debug_object_activate+0x63/0x4e0 lib/debugobjects.c:694
 debug_work_activate kernel/workqueue.c:509 [inline]
 __queue_work+0x951/0xd00 kernel/workqueue.c:1531
 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559
 release_task_stack kernel/fork.c:433 [inline]
 put_task_stack+0x97/0x140 kernel/fork.c:444
 finish_task_switch+0x276/0x630 kernel/sched/core.c:4942
 context_switch kernel/sched/core.c:5033 [inline]
 __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1890
 do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 kthread_stop+0x178/0x580 kernel/kthread.c:666
 destroy_workqueue+0xf2/0xae0 kernel/workqueue.c:4451
 xlog_cil_destroy+0xf9/0x140 fs/xfs/xfs_log_cil.c:1499
 xlog_dealloc_log+0xe7/0x270 fs/xfs/xfs_log.c:2063
 xfs_unmountfs+0x1bf/0x270 fs/xfs/xfs_mount.c:1040
 xfs_fs_put_super+0x65/0x2b0 fs/xfs/xfs_super.c:1095
 generic_shutdown_super+0x130/0x310 fs/super.c:475
 kill_block_super+0x7a/0xe0 fs/super.c:1427
 deactivate_locked_super+0xa0/0x110 fs/super.c:335
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa6e94e1497
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd8caea228 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fa6e9562854 RCX: 00007fa6e94e1497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd8caea2e0
RBP: 00007ffd8caea2e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd8caeb370
R13: 00007fa6e9562854 R14: 000000000007bb14 R15: 00007ffd8caeb3b0
 </TASK>