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:25216 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:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 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+0x662/0xf10 drivers/block/nbd.c:1207
 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2138
 __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+0xdac/0x1570 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:2376
 blk_mq_run_hw_queues+0x26c/0x3f0 block/blk-mq.c:2425
 blk_mq_requeue_work+0x717/0x760 block/blk-mq.c:1592
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/0:0H/11:
 #0: ffff888140ec1948 ((wq_completion)kblockd
){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90000107b80 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90000107b80 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffff888141bdb118 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline]
 #2: ffff888141bdb118 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline]
 #2: ffff888141bdb118 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2376
 #3: ffff888025148380 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1199
1 lock held by khungtaskd/31:
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5588:
 #0: ffff88814d4f60a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
1 lock held by udevd/22731:
 #0: ffff888025100358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by udevd/23393:
 #0: ffff8880252ab358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
2 locks held by syz.5.8195/2912:
 #0: ffff888051d39908 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff888051d39908 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
 #0: ffff888051d39908 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
 #1: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #1: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 2897 Comm: syz.3.8192 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x287/0x3b0 kernel/locking/lockdep.c:5892
Code: 24 08 48 c7 c7 63 93 97 8d e8 55 36 bd 09 b8 ff ff ff ff 65 0f c1 05 78 4c e0 10 83 f8 01 75 4d 48 c7 44 24 20 00 00 00 00 9c <8f> 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01
RSP: 0018:ffffc9000c067508 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000206 RCX: 06ef4e41ecbff700
RDX: 0000000000000003 RSI: ffffffff8d979363 RDI: ffffffff8bc08360
RBP: ffff88804fff8ba8 R08: ffffffff8233b88a R09: ffffffff8df41ae0
R10: dffffc0000000000 R11: fffff940001f3491 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8df41ae0 R15: ffff88804fff8000
FS:  0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b1b9b7198 CR3: 000000002f810000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock_sched include/linux/rcupdate.h:979 [inline]
 pfn_valid+0x3b2/0x490 include/linux/mmzone.h:2193
 page_table_check_clear+0x21/0x5f0 mm/page_table_check.c:70
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
 zap_present_folio_ptes mm/memory.c:1626 [inline]
 zap_present_ptes mm/memory.c:1708 [inline]
 do_zap_pte_range mm/memory.c:1810 [inline]
 zap_pte_range mm/memory.c:1854 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0x3257/0x4170 mm/memory.c:2017
 unmap_single_vma mm/memory.c:2059 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:2101
 exit_mmap+0x239/0xb10 mm/mmap.c:1277
 __mmput+0x118/0x430 kernel/fork.c:1173
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x658/0x2310 kernel/exit.c:959
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 __do_sys_exit_group kernel/exit.c:1123 [inline]
 __se_sys_exit_group kernel/exit.c:1121 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb2da58f749
Code: Unable to access opcode bytes at 0x7fb2da58f71f.
RSP: 002b:00007ffe2d7245b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb2da58f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe2d72461c R08: 000000122d7246af R09: 00000000000927c0
R10: 0000000000000144 R11: 0000000000000246 R12: 0000000000000157
R13: 00000000000927c0 R14: 00000000000b9ec4 R15: 00007ffe2d724670
 </TASK>