INFO: task kworker/0:0:8 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:22416 pid:8 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 wiphy_lock include/net/cfg80211.h:5777 [inline] reg_leave_invalid_chans net/wireless/reg.c:2451 [inline] reg_check_chans_work+0x10a/0xd90 net/wireless/reg.c:2466 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 INFO: task kworker/u4:15:9362 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:15 state:D stack:26376 pid:9362 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4718 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Showing all locks held in the system: 1 lock held by kthreadd/2: 4 locks held by kworker/0:0/8: #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc900000d7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900000d7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x92/0xd90 net/wireless/reg.c:2463 #3: ffff88801fb60768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5777 [inline] #3: ffff88801fb60768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: reg_leave_invalid_chans net/wireless/reg.c:2451 [inline] #3: ffff88801fb60768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: reg_check_chans_work+0x10a/0xd90 net/wireless/reg.c:2466 3 locks held by kworker/u4:1/12: 1 lock held by khungtaskd/29: #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 4 locks held by kworker/u4:2/31: 4 locks held by kworker/u4:3/49: #0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90000ba7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90000ba7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3b9990 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606 #3: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xd4/0x370 net/ipv4/ip_tunnel.c:1152 3 locks held by kworker/u4:4/61: 3 locks held by kworker/u4:6/147: 2 locks held by kworker/u4:8/1101: 4 locks held by kworker/u4:9/2997: 2 locks held by klogd/5129: 5 locks held by udevd/5140: 2 locks held by dhcpcd/5434: 4 locks held by dhcpcd/5435: 2 locks held by getty/5531: #0: ffff88814c7660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by syz-executor/5774: 3 locks held by kworker/1:5/6043: 2 locks held by syz-executor/6087: 4 locks held by kworker/1:8/7545: 2 locks held by kworker/1:10/7547: 2 locks held by kworker/1:11/7548: 3 locks held by kworker/1:12/7549: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000bcd7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000bcd7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by syz-executor/7776: 4 locks held by kworker/u4:10/9349: 2 locks held by kworker/u4:11/9351: 4 locks held by kworker/u4:12/9355: 5 locks held by kworker/u4:13/9357: 3 locks held by kworker/u4:14/9360: 3 locks held by kworker/u4:15/9362: #0: ffff88802cc04138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88802cc04138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90004c17d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90004c17d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4718 3 locks held by kworker/u4:16/9364: 2 locks held by kworker/u4:19/9369: 2 locks held by udevd/11316: 2 locks held by kworker/0:2/11774: 3 locks held by syz-executor/11776: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9357 Comm: kworker/u4:13 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_cmp8+0x0/0x80 kernel/kcov.c:293 Code: c0 4c 89 01 48 c7 44 11 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 88 7c 7e 65 8b 15 91 88 7c RSP: 0018:ffffc90000006c68 EFLAGS: 00000282 RAX: ffffffff813b3949 RBX: ffffffff81000000 RCX: ffff88802a5a8000 RDX: 0000000000000100 RSI: ffffffff81000000 RDI: ffffffff813b6901 RBP: ffffc90000006df8 R08: ffffc90000006e00 R09: 0000000000000000 R10: ffffc90000006da8 R11: fffff52000000dc1 R12: ffffc90000006da8 R13: dffffc0000000000 R14: ffffc90000006ddd R15: ffffffff813b6901 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b514a3ff8 CR3: 000000000cf32000 CR4: 00000000003506f0 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:206 [inline] unwind_next_frame+0x1c6/0x2970 arch/x86/kernel/unwind_orc.c:494 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] nlmsg_new include/net/netlink.h:1010 [inline] fdb_notify+0xa6/0x160 net/bridge/br_fdb.c:198 br_fdb_update+0x476/0x630 net/bridge/br_fdb.c:910 br_handle_frame_finish+0x5e5/0x18f0 net/bridge/br_input.c:141 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5540 __netif_receive_skb_one_core net/core/dev.c:5644 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5760 process_backlog+0x391/0x6f0 net/core/dev.c:6088 __napi_poll+0xc0/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6853 handle_softirqs+0x280/0x820 kernel/softirq.c:578 do_softirq+0xfa/0x1a0 kernel/softirq.c:479 __local_bh_enable_ip+0x184/0x1c0 kernel/softirq.c:406 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x776/0xb10 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293