INFO: task kworker/1:1H:97 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1H    state:D stack:26120 pid:97    tgid:97    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 wait_for_reconnect drivers/block/nbd.c:1104 [inline]
 nbd_handle_cmd drivers/block/nbd.c:1146 [inline]
 nbd_queue_rq+0x662/0xf10 drivers/block/nbd.c:1204
 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129
 __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+0xda4/0x1570 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:2367
 blk_mq_run_hw_queues+0x33e/0x430 block/blk-mq.c:2416
 blk_mq_requeue_work+0x717/0x760 block/blk-mq.c:1583
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 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:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/1:1H/97:
 #0: ffff88801fad5548 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88801fad5548 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9000212fba0 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9000212fba0 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffff88807975fe90 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #2: ffff88807975fe90 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #2: ffff88807975fe90 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2367
 #3: ffff88804fc34078 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
2 locks held by getty/5589:
 #0: ffff88814d1eb0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:3/3972:
5 locks held by kworker/u8:13/7823:
 #0: ffff88801aedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88801aedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9001a927ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9001a927ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8f2bf9f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:670
 #3: ffffffff8f2cc988 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
 #3: ffffffff8f2cc988 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248
 #4: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #4: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by udevd/23932:
 #0: ffff888032231358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
6 locks held by syz.3.12992/28894:

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

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 10/02/2025
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]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 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: 5817 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:aa_file_perm+0x1de/0x1550 security/apparmor/file.c:619
Code: 24 e8 06 c7 7a fd c6 05 ce 97 21 0b 01 48 c7 c7 00 b6 b8 8b be 65 03 00 00 48 c7 c2 40 b6 b8 8b e8 e7 3f 58 fd 4c 89 7c 24 48 <4c> 8d 73 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8
RSP: 0018:ffffc90003fefa00 EFLAGS: 00000293
RAX: ffffffff84453caf RBX: ffff888027fcab90 RCX: ffff888030159e40
RDX: 0000000000000000 RSI: ffffffff8bbf0840 RDI: ffffffff8bbf0800
RBP: ffffc90003fefbd0 R08: 0000000000000000 R09: ffffffff84453c6a
R10: dffffc0000000000 R11: ffffed1004f0b1e1 R12: dffffc0000000000
R13: ffffffff84453c6a R14: 0000000000000001 R15: ffff88807c8cf6c0
FS:  0000555559c6a500(0000) GS:ffff888126240000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff5b51b12f8 CR3: 000000007797e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 common_file_perm+0x1a9/0x230 security/apparmor/lsm.c:534
 security_file_permission+0x91/0x290 security/security.c:2913
 rw_verify_area+0xbb/0x4d0 fs/read_write.c:473
 vfs_read+0x154/0xa30 fs/read_write.c:563
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3131d8d99d
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d c1 ab 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffea2692f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3131d8d99d
RDX: 0000000000000004 RSI: 00007ffea2692f5c RDI: 0000000000000003
RBP: 0000000000000000 R08: 7fffffffffffffff R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffea2693370
R13: 0000000000000004 R14: 00007ffea2692f5c R15: 00007ffea2692ff0
 </TASK>