INFO: task kworker/0:4:5923 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:21312 pid:5923 tgid:5923 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: 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_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 class_wiphy_constructor include/net/cfg80211.h:6363 [inline] reg_leave_invalid_chans net/wireless/reg.c:2441 [inline] reg_check_chans_work+0x156/0xf00 net/wireless/reg.c:2456 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 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 INFO: task kworker/u8:13:5996 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:13 state:D stack:23264 pid:5996 tgid:5996 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: 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_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 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 Showing all locks held in the system: 1 lock held by kthreadd/2: 4 locks held by kworker/0:0/9: 3 locks held by kworker/0:1/10: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc900000f7b80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffffffff8f305bc8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:0/12: 4 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/34: 3 locks held by kworker/u8:3/49: 3 locks held by kworker/u8:4/79: 3 locks held by kworker/u8:5/153: 4 locks held by kworker/1:2/912: #0: ffff88805a8fcd48 ((wq_completion)wg-kex-wg0#14){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90003b57b80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888034b45348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff88807b57f030 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632 4 locks held by kworker/u8:6/1004: 3 locks held by kworker/u8:7/1146: 2 locks held by kworker/u8:9/3452: 2 locks held by kworker/u8:10/3560: 1 lock held by klogd/5184: 2 locks held by udevd/5195: 2 locks held by getty/5579: #0: ffff88814c7c20a0 (&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 syz-executor/5811: 3 locks held by syz-executor/5821: 4 locks held by syz-executor/5822: 4 locks held by kworker/1:3/5827: #0: ffff88805affa948 ((wq_completion)wg-kex-wg2#12){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc9000412fb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff88804f875348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0x11a/0x8f0 drivers/net/wireguard/noise.c:678 #3: ffff88807b57e648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_response+0x12b/0x8f0 drivers/net/wireguard/noise.c:679 4 locks held by kworker/1:4/5844: #0: ffff88807b1d1948 ((wq_completion)wg-kex-wg1#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc9000421fb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888034549348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff88805b631708 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632 8 locks held by kworker/1:5/5902: 4 locks held by kworker/1:6/5915: 2 locks held by kworker/1:7/5916: 4 locks held by kworker/0:4/5923: #0: ffff88813fe56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc900046afb80 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffffffff8f305bc8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa1/0xf00 net/wireless/reg.c:2453 #3: ffff888053590788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline] #3: ffff888053590788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2441 [inline] #3: ffff888053590788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x156/0xf00 net/wireless/reg.c:2456 3 locks held by kworker/0:5/5944: #0: ffff88805a8fcd48 ((wq_completion)wg-kex-wg0#14){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc9000471fb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff88807b57f030 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x36/0xbd0 drivers/net/wireguard/noise.c:822 4 locks held by kworker/0:6/5945: 4 locks held by kworker/u8:11/5965: 2 locks held by kworker/u8:12/5981: 3 locks held by kworker/u8:13/5996: #0: ffff88814c6a9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90004c1fb80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffffffff8f305bc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f305bc8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 4 locks held by kworker/u8:14/6022: 3 locks held by kworker/u8:15/6026: 3 locks held by kworker/0:9/6045: 3 locks held by kworker/u8:16/6046: 2 locks held by kworker/1:11/6052: 4 locks held by kworker/u8:17/6116: 4 locks held by kworker/0:10/6157: 2 locks held by kworker/u8:18/6163: 3 locks held by kworker/u8:19/6188: 3 locks held by kworker/u8:20/6322: 2 locks held by kworker/1:13/6323: 4 locks held by kworker/1:14/6383: 3 locks held by kworker/u8:21/6479: 3 locks held by kworker/0:11/6532: 3 locks held by kworker/u8:22/6656: 1 lock held by syz-executor/6816: 3 locks held by syz-executor/7466: 2 locks held by syz.3.339/7746: 2 locks held by syz.3.340/7755: 4 locks held by kworker/0:12/7912: #0: ffff888031c10d48 ((wq_completion)wg-kex-wg2#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc900040dfb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff88803454d348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff88805b632ad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632 6 locks held by syz.1.372/7925: 4 locks held by kworker/0:13/7932: 2 locks held by udevd/7941: 4 locks held by kworker/1:15/7942: 3 locks held by cmp/7950: 4 locks held by kworker/u8:23/7953: 3 locks held by kworker/u8:24/7954: 5 locks held by kworker/0:14/7955: 4 locks held by kworker/0:15/7957: #0: ffff88805d73c148 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90003d7fb80 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff88805d3a5348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff88805b633ea8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4bf/0x900 drivers/net/wireguard/noise.c:632 4 locks held by kworker/u8:25/7958: ============================================= 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 10/25/2025 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] __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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5902 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker RIP: 0010:in_task_stack+0x1f/0x40 arch/x86/kernel/dumpstack.c:36 Code: 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 8b 4e 20 48 8d b1 00 80 00 00 48 39 cf 41 0f 93 c0 48 39 f7 0f 92 c0 44 20 c0 <3c> 01 75 16 c7 02 01 00 00 00 48 89 4a 08 48 89 72 10 48 c7 42 18 RSP: 0018:ffffc90000a07c50 EFLAGS: 00000202 RAX: 1ffff92000140f01 RBX: ffffc90000a07da8 RCX: ffffc900045b8000 RDX: ffffc90000a07d88 RSI: ffffc900045c0000 RDI: ffffc900045bf1b8 RBP: 1ffff92000140fb2 R08: 0000000000000001 R09: ffffffff8df419e0 R10: ffffc90000a07dd8 R11: ffffffff81ada230 R12: ffff88802f488000 R13: 1ffff92000140fb3 R14: ffffc90000a07d88 R15: ffffc900045bf1b8 FS: 0000000000000000(0000) GS:ffff888125f49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd3828ef68 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: get_stack_info_noinstr+0x1b/0x130 arch/x86/kernel/dumpstack_64.c:173 get_stack_info+0x3b/0xf0 arch/x86/kernel/dumpstack_64.c:199 stack_access_ok arch/x86/kernel/unwind_orc.c:396 [inline] deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0xba5/0x2390 arch/x86/kernel/unwind_orc.c:585 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5265 skb_clone+0x212/0x3a0 net/core/skbuff.c:2087 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x414/0x6a0 net/bridge/br_forward.c:250 br_handle_frame_finish+0x15a3/0x1c90 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 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+0x96e/0x14f0 net/bridge/br_input.c:442 __netif_receive_skb_core+0x95f/0x2f90 net/core/dev.c:6025 __netif_receive_skb_one_core net/core/dev.c:6136 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6251 process_backlog+0x622/0x1500 net/core/dev.c:6603 __napi_poll+0xae/0x320 net/core/dev.c:7667 napi_poll net/core/dev.c:7730 [inline] net_rx_action+0x672/0xe50 net/core/dev.c:7882 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] wg_index_hashtable_insert+0xff/0x880 drivers/net/wireguard/peerlookup.c:126 wg_noise_handshake_create_response+0x69a/0x8f0 drivers/net/wireguard/noise.c:713 wg_packet_send_handshake_response+0xf6/0x2d0 drivers/net/wireguard/send.c:94 wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline] wg_packet_handshake_receive_worker+0x623/0xfc0 drivers/net/wireguard/receive.c:213 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 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