INFO: tas[  707.160554][   T37] INFO: task syz.2.678:11156 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.678       state:D stack:25640 pid:11156 tgid:11152 ppid:5602   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1579
 __alloc_workqueue+0x16b2/0x2060 kernel/workqueue.c:5924
 alloc_workqueue_va kernel/workqueue.c:5946 [inline]
 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5962
 btrfs_alloc_ordered_workqueue+0x1c3/0x290 fs/btrfs/async-thread.c:140
 btrfs_init_workqueues+0x345/0x630 fs/btrfs/disk-io.c:1985
 open_ctree+0x1503/0x41c0 fs/btrfs/disk-io.c:3514
 btrfs_fill_super fs/btrfs/super.c:983 [inline]
 btrfs_get_tree_super fs/btrfs/super.c:1974 [inline]
 btrfs_get_tree_subvol fs/btrfs/super.c:2117 [inline]
 btrfs_get_tree+0x1084/0x1980 fs/btrfs/super.c:2151
 vfs_get_tree+0x92/0x2a0 fs/super.c:1700
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d95b1f28a
RSP: 002b:00007f6d93d75e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6d93d75ee0 RCX: 00007f6d95b1f28a
RDX: 0000200000005100 RSI: 0000200000000000 RDI: 00007f6d93d75ea0
RBP: 0000200000005100 R08: 00007f6d93d75ee0 R09: 0000000000000810
R10: 0000000000000810 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f6d93d75ea0 R14: 000000000000512d R15: 0000200000000080
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/37:
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5349:
 #0: ffff888032b300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
1 lock held by udevd/5587:
1 lock held by syz.2.678/11156:
 #0: ffff888064ac00d0 (&type->s_umount_key#57/1){+.+.}-{4:4}, at: alloc_super fs/super.c:345 [inline]
 #0: ffff888064ac00d0 (&type->s_umount_key#57/1){+.+.}-{4:4}, at: sget_fc+0x938/0x1910 fs/super.c:766
3 locks held by kworker/1:0/11675:
5 locks held by syz.1.898/12751:
1 lock held by syz.3.897/12741:
4 locks held by syz.0.902/12773:
3 locks held by syz.5.901/12776:
3 locks held by syz.4.903/12782:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 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: 11675 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_power_efficient gc_worker
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:lockdep_hardirqs_on+0x4b/0x110 kernel/locking/lockdep.c:4460
Code: 5a 07 a9 00 00 f0 00 75 41 65 8b 05 47 70 5a 07 85 c0 75 6b 65 8b 05 dc 6a 5a 07 85 c0 75 60 83 3d c9 6f 65 0e 00 75 22 9c 58 <a9> 00 02 00 00 75 57 83 3d b7 6f 65 0e 00 75 10 48 8b 83 e0 0b 00
RSP: 0000:ffffc9001d20f970 EFLAGS: 00000046
RAX: 0000000000000046 RBX: ffff888030155d00 RCX: 0000000000000046
RDX: 0000000000000006 RSI: ffffffff8daf6c22 RDI: ffffffff8967505a
RBP: ffffc9001d20faf0 R08: ffffffff8fafa337 R09: 1ffffffff1f5f466
R10: dffffc0000000000 R11: fffffbfff1f5f467 R12: ffff88805ed87c18
R13: dffffc0000000000 R14: 0000000000000200 R15: 00000000000203f3
FS:  0000000000000000(0000) GS:ffff888125d3e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32dfcff8 CR3: 000000000dfb0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
 arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
 arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
 seqcount_lockdep_reader_access+0xaa/0x100 include/linux/seqlock.h:75
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline]
 gc_worker+0x322/0x18b0 net/netfilter/nf_conntrack_core.c:1534
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>