INFO: task kworker/1:0H:25 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0H    state:D stack:26568 pid:25    tgid:25    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d4/0x5630 kernel/sched/core.c:7239
 __schedule_loop kernel/sched/core.c:7316 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7331
 schedule_timeout+0x152/0x2c0 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+0x889/0x1150 drivers/block/nbd.c:1207
 blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
 __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+0xd36/0x1580 block/blk-mq-sched.c:307
 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
 blk_mq_run_hw_queue+0x34a/0x4f0 block/blk-mq.c:2356
 blk_mq_run_hw_queues+0x268/0x3f0 block/blk-mq.c:2404
 blk_mq_requeue_work+0x703/0x760 block/blk-mq.c:1571
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x38b/0x480 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>

Showing all locks held in the system:
locks held by kworker/1:0H/25: 4, on CPU#1:
 #0: ffff88801f2a3140 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88801f2a3140 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #1: ffffc900001f7c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc900001f7c40 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #2: ffff888026d10a18 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #2: ffff888026d10a18 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #2: ffff888026d10a18 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x321/0x4f0 block/blk-mq.c:2355
 #3: ffff888026dbe178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc1/0x1150 drivers/block/nbd.c:1199
locks held by khungtaskd/30: 1, last CPU#0:
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793
locks held by getty/5369: 2, on CPU#1:
 #0: ffff8880367740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/5849: 1, on CPU#1:
 #0: ffff88802676f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:991
locks held by kworker/u8:25/11116: 3, last CPU#1:
 #0: ffff8880327cf940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff8880327cf940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #1: ffffc90005ae7c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc90005ae7c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0 kernel/workqueue.c:3405
 #2: ffff8880b8728198 (hrtimer_bases.lock){-.-.}-{2:2}, at: class_raw_spinlock_constructor include/linux/spinlock.h:559 [inline]
 #2: ffff8880b8728198 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_rearm_deferred+0x99/0x4b0 kernel/time/hrtimer.c:2181
locks held by syz.3.2570/14793: 2, on CPU#0:
 #0: ffffffff90036540 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
 #0: ffffffff90036540 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3587
 #1: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #1: ffffffff8eb604e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
locks held by dhcpcd-run-hook/14826: 4, last CPU#0:
 #0: ffff8880b863b4e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
 #1: ffffffff9a7d6748 (&____s->seqcount#2){----}-{0:0}, at: ktime_get_real_ts64+0xa9/0x3d0 kernel/time/timekeeping.c:980
 #2: ffff8880767a4eb8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline]
 #2: ffff8880767a4eb8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
 #3: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #3: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #3: ffffffff8eb5a1e0 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x127/0x530 mm/page_table_check.c:112
locks held by sed/14827: 1, last CPU#0:
 #0: ffff8880b863b4e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(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:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0x38b/0x480 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: 11116 Comm: kworker/u8:25 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d 14 73 8b 0c 48 89 de 5b e9 23 b7 63 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d a8 e2 a8 11 65 48 8b 15 a8 e2
RSP: 0018:ffffc90000a08d00 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888034898000
RDX: 8000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000120dc R08: 0000000000000100 R09: 0000000000080000
R10: 0000000000000000 R11: ffffffff9a7d6748 R12: 1ffff920001411ac
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125021000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fec56a11b60 CR3: 0000000073e9e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 ktime_get+0x67/0x220 kernel/time/timekeeping.c:1002
 clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363
 hrtimer_rearm kernel/time/hrtimer.c:2169 [inline]
 __hrtimer_rearm_deferred+0x36c/0x4b0 kernel/time/hrtimer.c:2189
 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:58 [inline]
 hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:67 [inline]
 irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
 irqentry_exit+0x8d3/0x910 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221
Code: f7 e8 6d a5 c7 f5 f7 c3 00 02 00 00 74 05 e8 70 b3 f3 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 54 c7 b8 f5 65 48 8b 05 4c 50 94 07 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000a08f40 EFLAGS: 00000206
RAX: 0000000000000016 RBX: 0000000000000283 RCX: 8000000000000102
RDX: 0000000000000002 RSI: ffffffff8e258909 RDI: 0000000000000001
RBP: 0000000000000002 R08: ffffffff90589437 R09: 1ffffffff20b1286
R10: dffffc0000000000 R11: fffffbfff20b1287 R12: 0000000000000009
R13: 0000000000000008 R14: ffff8880b8728180 R15: 0000000000000100
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 do_softirq+0x77/0xd0 kernel/softirq.c:546
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
 spin_unlock_bh include/linux/spinlock.h:407 [inline]
 batadv_tt_local_purge+0x2c1/0x340 net/batman-adv/translation-table.c:1402
 batadv_tt_purge+0x35/0xa10 net/batman-adv/translation-table.c:3753
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x38b/0x480 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>