INFO: task syz.0.16:5079 blocked for more than 143 seconds.
      Not tainted 5.15.189-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:27296 pid: 5079 ppid:  4778 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
 do_wait_for_common+0x29a/0x440 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
 flush_workqueue+0x63a/0x1380 kernel/workqueue.c:2882
 nbd_start_device_ioctl drivers/block/nbd.c:1365 [inline]
 __nbd_ioctl drivers/block/nbd.c:1427 [inline]
 nbd_ioctl+0xaea/0xe40 drivers/block/nbd.c:1467
 blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
 block_ioctl+0xac/0xf0 block/fops.c:496
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9363536929
RSP: 002b:00007f93627a6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f936375dfa0 RCX: 00007f9363536929
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f93635b8b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f936375dfa0 R15: 00007ffd74928888
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u5:0/146:
 #0: ffff888020dd1138 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000171fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
3 locks held by klogd/3552:
 #0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffffff8c1ec800 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline]
 #1: ffffffff8c1ec800 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __wake_up_sync_key+0xf0/0x180 kernel/sched/wait.c:205
 #2: ffff88807e7f27e8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x5c/0x1050 kernel/sched/core.c:4030
2 locks held by getty/3948:
 #0: ffff88814d5d0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by kworker/u5:2/4287:
 #0: ffff888020cc2938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900031cfd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:3/5086:
 #0: ffff888020d1a938 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000315fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:4/5110:
 #0: ffff888020dfb938 ((wq_completion)nbd5-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000333fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:5/5132:
 #0: ffff888020dd7938 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000343fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:6/5162:
 #0: ffff888020dee138 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900035afd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:7/5192:
 #0: ffff888020f46138 ((wq_completion)nbd8-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000359fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:8/5221:
 #0: ffff888020e9a138 ((wq_completion)nbd6-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900037bfd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:9/5251:
 #0: ffff8881476a8938 ((wq_completion)nbd7-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900038bfd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
2 locks held by kworker/u5:10/5285:
 #0: ffff888021021138 ((wq_completion)nbd9-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900039afd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 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+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: phy28 ieee80211_iface_work
RIP: 0010:__this_cpu_preempt_check+0x3/0x10 lib/smp_processor_id.c:66
Code: e8 82 70 f5 ff 48 8b 74 24 30 48 c7 c7 c0 93 59 8a e8 71 70 f5 ff e8 cc 20 f8 ff eb a8 e8 d5 ee ff ff 0f 1f 44 00 00 48 89 fe <48> c7 c7 40 93 59 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48 89 f8 48
RSP: 0018:ffffc90000ce7b58 EFLAGS: 00000046
RAX: 1ffff11027fda159 RBX: ffffffffffffffff RCX: ffffffff960bdf03
RDX: dffffc0000000000 RSI: ffffffff8a0b23c0 RDI: ffffffff8a0b23c0
RBP: ffffc90000ce7c10 R08: dffffc0000000000 R09: ffffed1002d0f301
R10: ffffed1002d0f301 R11: 1ffff11002d0f300 R12: dffffc0000000000
R13: ffff88807954d7c0 R14: ffff88813fed0000 R15: ffff888016879800
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555561c0f5c8 CR3: 000000002a631000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
 lockdep_hardirqs_on_prepare+0x1b4/0x760 kernel/locking/lockdep.c:4277
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
 _raw_spin_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:202
 process_one_work+0x758/0x1000 kernel/workqueue.c:2283
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>