INFO: task kworker/u8:7:2962 blocked for more than 149 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:7 state:D stack:20832 pid:2962 tgid:2962 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 netdev_wait_allrefs_any net/core/dev.c:11455 [inline] netdev_run_todo+0x721/0xea0 net/core/dev.c:11575 default_device_exit_batch+0x81e/0x890 net/core/dev.c:12815 ops_exit_list net/core/net_namespace.c:204 [inline] ops_undo_list+0x522/0x990 net/core/net_namespace.c:251 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/1:14:8170 blocked for more than 151 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:14 state:D stack:24072 pid:8170 tgid:8170 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 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: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 1 lock held by khungtaskd/31: #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/2962: #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000bb47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000bb47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11455 [inline] #3: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x721/0xea0 net/core/dev.c:11575 2 locks held by getty/5621: #0: ffff8880301c60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000362c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:6/5980: #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004eefbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004eefbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf30 net/wireless/reg.c:2483 3 locks held by kworker/1:14/8170: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000bc77bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000bc77bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz-executor/16289: #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433 3 locks held by kworker/u8:18/20236: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000f1e7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000f1e7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/u8:24/20243: #0: ffff88802fa31148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88802fa31148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000d867bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000d867bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 5 locks held by kworker/u8:25/20245: 1 lock held by syz.4.4078/21083: #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433 2 locks held by syz.3.4092/21146: #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.3.4092/21155: #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 ============================================= 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 08/18/2025 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 20245 Comm: kworker/u8:25 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound toggle_allocation_gate 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_is_held_type+0x119/0x190 kernel/locking/lockdep.c:5942 Code: 00 00 00 48 c7 c7 3d 99 ba 8d e8 92 16 00 00 b8 ff ff ff ff 65 0f c1 05 35 04 26 07 83 f8 01 75 44 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb RSP: 0018:ffffc9000d8475b0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: fc0cedda9ac6cd00 RDX: 0000000000000000 RSI: ffffffff8dba993d RDI: ffffffff8be33f00 RBP: 00000000ffffffff R08: ffffc9000d847847 R09: 0000000000000000 R10: ffffc9000d847820 R11: fffff52001b08f09 R12: 0000000000000246 R13: ffff888025993c00 R14: ffffffff8e13a1a0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6a437e6038 CR3: 000000008e41a000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0xf5/0x610 kernel/sched/core.c:8919 __mutex_lock_common kernel/locking/mutex.c:575 [inline] __mutex_lock+0x109/0x1350 kernel/locking/mutex.c:760 arch_jump_label_transform_queue+0x5f/0x110 arch/x86/kernel/jump_label.c:136 __jump_label_update+0x185/0x3a0 kernel/jump_label.c:513 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245