INFO: task kworker/0:0H:11 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0H    state:D stack:26536 pid:11    tgid:11    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7005
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 wait_for_reconnect drivers/block/nbd.c:1107 [inline]
 nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
 nbd_queue_rq+0x857/0x1100 drivers/block/nbd.c:1207
 blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
 __blk_mq_sched_dispatch_requests+0xdcc/0x1600 block/blk-mq-sched.c:307
 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
 blk_mq_run_hw_queues+0x26c/0x3f0 block/blk-mq.c:2435
 blk_mq_requeue_work+0x71c/0x780 block/blk-mq.c:1602
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/0:0H/11:
 #0: ffff888020280d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff888020280d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90000107c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90000107c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffff8880258cb718 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #2: ffff8880258cb718 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #2: ffff8880258cb718 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2386
 #3: ffff888026d88580 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199
4 locks held by kworker/1:1/29:
 #0: ffff8880b873ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #2: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #2: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 #2: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495
 #3: ffff88801ded0a90 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:570 [inline]
 #3: ffff88801ded0a90 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x66/0x1390 kernel/sched/core.c:4130
1 lock held by khungtaskd/31:
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5590:
 #0: ffff8880341db0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5886:
 #0: ffff888026ce6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
3 locks held by syz.4.2812/16519:
1 lock held by syz.3.2814/16526:
 #0: ffffffff8fbc7508 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8fbc7508 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
4 locks held by syz.1.2817/16548:
 #0: ffff888049abbb88 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #0: ffff888049abbb88 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
 #0: ffff888049abbb88 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1454
 #1: ffffffff8fc33970 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379
 #2: ffff8880344174d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x13d/0xdb0 net/netfilter/nf_tables_api.c:11926
 #3: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #3: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
 watchdog+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 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: 5174 Comm: syslogd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:lockdep_hardirqs_off+0x81/0xd0 kernel/locking/lockdep.c:4495
Code: c7 05 f7 3d 6d 07 00 00 00 00 49 89 9e 00 0b 00 00 41 8b 86 f0 0a 00 00 ff c0 41 89 86 f0 0a 00 00 41 89 86 0c 0b 00 00 eb 17 <48> c7 c7 f8 ee f5 8d e8 53 19 00 00 65 8b 05 3c 41 6d 07 85 c0 74
RSP: 0018:ffffc90002fa7830 EFLAGS: 00000046
RAX: 0000000080000000 RBX: ffffffff822fe8cf RCX: 0000000000000000
RDX: ffff88805729e400 RSI: ffff88805729e400 RDI: ffffffff822fe8cf
RBP: 0000000000000000 R08: 000000006b20c98b R09: 000000002947302c
R10: 000000000000000d R11: ffffffff81b0bb70 R12: ffff88805729e400
R13: 0000000000000000 R14: ffff88813fe00140 R15: 0000000000000286
FS:  00007fcdf7d21c80(0000) GS:ffff888125565000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31009ff8 CR3: 0000000030436000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104
 kasan_quarantine_put+0x2f/0x1f0 mm/kasan/quarantine.c:207
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free mm/slub.c:6143 [inline]
 kfree+0x1c1/0x630 mm/slub.c:6461
 skb_kfree_head net/core/skbuff.c:1078 [inline]
 skb_free_head net/core/skbuff.c:1090 [inline]
 skb_release_data+0x6f0/0x940 net/core/skbuff.c:1117
 skb_release_all net/core/skbuff.c:1192 [inline]
 __kfree_skb+0x5d/0x210 net/core/skbuff.c:1206
 __unix_dgram_recvmsg+0x9d0/0xd50 net/unix/af_unix.c:2653
 sock_recvmsg_nosec net/socket.c:1077 [inline]
 sock_recvmsg+0x172/0x1b0 net/socket.c:1099
 sock_read_iter+0x251/0x320 net/socket.c:1169
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x582/0xa70 fs/read_write.c:574
 ksys_read+0x150/0x270 fs/read_write.c:717
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcdf7e71407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc16d91b50 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fcdf7d21c80 RCX: 00007fcdf7e71407
RDX: 00000000000000ff RSI: 000055feaca17950 RDI: 0000000000000000
RBP: 000055feaca17910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055feaca1799c
R13: 0000000000000000 R14: 000055feaca17950 R15: 000055fe91c00d98
 </TASK>