INFO: task kworker/1:1H:56 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:56 tgid:56 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: kblockd blk_mq_requeue_work Call Trace: 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 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by rcu_tasks_trace/29: #0: ffffffff8e13e010 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614 1 lock held by khungtaskd/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/1:1H/56: #0: ffff8880202a9d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8880202a9d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000131fba0 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000131fba0 ((work_completion)(&(&q->requeue_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888024b7e790 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #2: ffff888024b7e790 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #2: ffff888024b7e790 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2367 #3: ffff888024d776b8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196 2 locks held by getty/5591: #0: ffff88814d9550a0 (&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 1 lock held by udevd/6416: #0: ffff888143b72358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 4 locks held by kworker/u8:10/14019: #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90002ea7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90002ea7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4d2eb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11462 [inline] #3: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x721/0xea0 net/core/dev.c:11582 3 locks held by kworker/u8:13/14022: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900023efba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900023efba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by syz.4.4060/20489: #0: ffff88805ab6c148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff88805ab6c148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88805ab6c148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: raw_release+0x1bc/0xa10 net/can/raw.c:418 1 lock held by syz.0.4065/20515: #0: ffff888056acc148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888056acc148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff888056acc148 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 3 locks held by syz.3.4070/20534: #0: ffff888056acb008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888056acb008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff888056acb008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8f543e50 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff88805a2998d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x116/0x640 net/netfilter/nf_tables_api.c:12087 6 locks held by syz.2.4069/20538: #0: ffffffff8f5459d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88805a4be0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #1: ffff88805a4be0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #1: ffff88805a4be0e8 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x240/0x3a0 net/devlink/netlink.c:198 #2: ffff88805a4b9250 (&devlink->lock_key#8){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #2: ffff88805a4b9250 (&devlink->lock_key#8){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x24f/0x3a0 net/devlink/netlink.c:198 #3: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670 drivers/net/netdevsim/netdev.c:1173 #4: ffff88806b29cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2765 [inline] #4: ffff88806b29cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x564/0x2390 net/core/dev.c:12244 #5: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #5: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.1.4071/20540: #0: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3078 1 lock held by syz.1.4071/20543: #0: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6957 1 lock held by syz.1.4071/20544: #0: ffffffff8f4dfd48 (rtnl_mutex){+.+.}-{4:4}, at: tc_new_tfilter+0x4b5/0x15b0 net/sched/cls_api.c:2308 ============================================= 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: 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5815 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:__timerqueue_less lib/timerqueue.c:22 [inline] RIP: 0010:rb_add_cached include/linux/rbtree.h:174 [inline] RIP: 0010:timerqueue_add+0xba/0x200 lib/timerqueue.c:40 Code: 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 5b ec dd f6 4d 8b 3f b3 01 48 8d 7d 18 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 3f ec dd f6 4c 8b 65 18 4c 89 ff 4c 89 e6 e8 70 3e 78 f6 RSP: 0018:ffffc90003fc7b00 EFLAGS: 00000046 RAX: 1ffff920036b4fab RBX: 1ffff110170e4f01 RCX: ffff888076338000 RDX: 0000000000000000 RSI: 0000005767f48d0a RDI: ffffc9001b5a7d58 RBP: ffffc9001b5a7d40 R08: ffffffff8f9e1477 R09: 1ffffffff1f3c28e R10: dffffc0000000000 R11: fffffbfff1f3c28f R12: ffffc9001b5a7d40 R13: dffffc0000000000 R14: 0000000000000001 R15: 00000057318a77dd FS: 000055558fbb9500(0000) GS:ffff888125e0c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc03c7b4198 CR3: 0000000074320000 CR4: 00000000003526f0 Call Trace: __hrtimer_start_range_ns kernel/time/hrtimer.c:1263 [inline] hrtimer_start_range_ns+0xcea/0x1080 kernel/time/hrtimer.c:1322 hrtimer_start_expires include/linux/hrtimer.h:273 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2039 [inline] do_nanosleep+0x18c/0x610 kernel/time/hrtimer.c:2113 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2163 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375 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: 0033:0x7f8d57bc1843 Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 1e 6d 1f 00 00 74 14 b8 e6 00 00 00 0f 05 d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10 RSP: 002b:00007ffc55f679d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8d57bc1843 RDX: 00007ffc55f679f0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 7fffffffffffffff R09: 3fffffffffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc55f67e40 R13: 0000000000000004 R14: 00007ffc55f67a2c R15: 00007ffc55f67ac0