INFO: task kworker/1:4:5824 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:20576 pid:5824 tgid:5824 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1522/0x51d0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 class_wiphy_constructor include/net/cfg80211.h:6360 [inline] reg_leave_invalid_chans net/wireless/reg.c:2441 [inline] reg_check_chans_work+0x15a/0xf40 net/wireless/reg.c:2456 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 1 lock held by kthreadd/2: 1 lock held by khungtaskd/31: #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/R-ipv6_/3183: #0: ffff88802fbbe148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88802fbbe148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000bc87b80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000bc87b80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 2 locks held by kworker/R-bat_e/3408: 2 locks held by klogd/5183: 2 locks held by udevd/5194: 1 lock held by dhcpcd/5488: 5 locks held by dhcpcd/5489: 3 locks held by crond/5563: 2 locks held by getty/5575: #0: ffff88803085e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036be2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by kworker/1:4/5824: #0: ffff88813fe56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90003e2fbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90003e2fbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa5/0xf40 net/wireless/reg.c:2453 #3: ffff888064bd8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6360 [inline] #3: ffff888064bd8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2441 [inline] #3: ffff888064bd8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x15a/0xf40 net/wireless/reg.c:2456 7 locks held by kworker/u8:14/9700: 3 locks held by kworker/u8:17/10155: 4 locks held by kworker/u8:19/14364: 3 locks held by kworker/0:8/15114: 8 locks held by kworker/1:2/15118: 2 locks held by kworker/1:12/15124: 4 locks held by kworker/1:13/15125: 3 locks held by kworker/u8:1/23171: 4 locks held by kworker/u8:3/23172: 4 locks held by kworker/u8:6/23176: 4 locks held by kworker/1:0/23322: 3 locks held by kworker/u8:7/25363: 4 locks held by kworker/u8:10/25364: #0: ffff888057120148 ((wq_completion)wg-kex-wg1#31){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888057120148 ((wq_completion)wg-kex-wg1#31){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000b897bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000b897bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff88805974d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12f/0x830 drivers/net/wireguard/noise.c:529 #3: ffff888059934890 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x140/0x830 drivers/net/wireguard/noise.c:530 3 locks held by kworker/u8:13/25372: 3 locks held by kworker/0:1/29034: 3 locks held by kworker/0:2/30397: 4 locks held by syz-executor/4915: 4 locks held by kworker/u8:0/8718: #0: ffff88801efa5148 ((wq_completion)wg-kex-wg0#31){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801efa5148 ((wq_completion)wg-kex-wg0#31){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000428fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000428fbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff88802ead5308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12f/0x830 drivers/net/wireguard/noise.c:529 #3: ffff8880599334c0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x140/0x830 drivers/net/wireguard/noise.c:530 3 locks held by syz-executor/16191: 1 lock held by syz.1.5919/16809: #0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956 3 locks held by kworker/1:1/21856: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900040ffbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900040ffbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956 3 locks held by syz.1.6682/24079: 4 locks held by kworker/u8:2/27929: #0: ffff8880538af148 ((wq_completion)wg-kex-wg1#33){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff8880538af148 ((wq_completion)wg-kex-wg1#33){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000efa7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000efa7bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff88805c0b5308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12f/0x830 drivers/net/wireguard/noise.c:529 #3: ffff888059067030 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x140/0x830 drivers/net/wireguard/noise.c:530 2 locks held by kworker/0:0/29458: 3 locks held by kworker/0:4/30632: 6 locks held by syz.0.7526/31605: 4 locks held by udevd/31606: 4 locks held by kworker/1:3/31608: 3 locks held by kworker/u8:4/31609: 3 locks held by syz-executor/31611: 3 locks held by kworker/u8:5/31614: 3 locks held by kworker/0:5/31615: 4 locks held by kworker/u8:8/31616: 3 locks held by kworker/u8:9/31623: 3 locks held by syz-executor/31624: 2 locks held by kworker/1:5/31625: 1 lock held by kworker/u8:11/31626: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9700 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rcu_lockdep_current_cpu_online+0x25/0x120 kernel/rcu/tree.c:4025 Code: 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 8b 0d a0 df 48 11 b0 01 f7 c1 00 00 f0 00 0f 85 d5 00 00 00 83 3d e3 30 45 0e 00 <0f> 84 c8 00 00 00 65 ff 05 7e df 48 11 e8 79 48 ed 09 89 c3 83 f8 RSP: 0018:ffffc90000a07fd0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000102 RDX: ffff8880446bdb80 RSI: ffffffff8c073ae0 RDI: ffffffff8c073aa0 RBP: ffffc90000a080b8 R08: ffff8880446bdb80 R09: 0000000000000002 R10: 000000000000000a R11: 0000000000000100 R12: 1ffff92000141004 R13: dffffc0000000000 R14: ffff88806ad1c0c0 R15: ffff8880a0056a00 FS: 0000000000000000(0000) GS:ffff8881257f3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f347417e000 CR3: 0000000077d1a000 CR4: 00000000003526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 __in6_dev_get include/net/addrconf.h:347 [inline] br_validate_ipv6+0xe3/0x740 net/bridge/br_netfilter_ipv6.c:46 br_nf_forward_ip+0x464/0xa30 net/bridge/br_netfilter_hooks.c:705 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x30a0 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb net/core/dev.c:6265 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6617 __napi_poll+0xae/0x340 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7896 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1b7/0x390 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:921 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246