INFO: task kworker/1:6:18970 blocked for more than 156 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:6 state:D stack:23496 pid:18970 tgid:18970 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 3 locks held by kworker/0:0/9: 3 locks held by kworker/0:1/10: 3 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: #0: ffff888034b3c940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90000ac7d08 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4746 6 locks held by kworker/u8:4/57: #0: ffff88801c6c0940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc900015e7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff905f21a8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673 #3: ffff88805840f128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88805840f128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff88805840f128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x19e/0x370 net/devlink/core.c:555 #4: ffff8880584ae258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff8880584ae258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff8880584ae258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x1b4/0x370 net/devlink/core.c:555 #5: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2162 4 locks held by kworker/u8:6/1094: 4 locks held by kworker/u8:7/1107: 1 lock held by dhcpcd/5272: 2 locks held by getty/5366: #0: ffff888034da00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5674: #0: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3438 1 lock held by syz-executor/5684: 3 locks held by kworker/0:3/5783: 3 locks held by kworker/1:9/5905: 1 lock held by syz.0.5626/18258: #0: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3438 2 locks held by kworker/1:5/18969: 3 locks held by kworker/1:6/18970: #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90003d97d08 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/1:7/18990: 6 locks held by syz.1.6079/19852: 3 locks held by kworker/u8:8/19958: 3 locks held by kworker/u8:9/19959: #0: ffff88813fe94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90008327d08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff9060aee0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313 1 lock held by syz-executor/19972: 3 locks held by kworker/u8:12/19991: 3 locks held by kworker/u8:14/19995: 4 locks held by kworker/u8:15/20007: #0: ffff888077b72140 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000787fd08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff8880373093c0 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x610 drivers/net/wireguard/noise.c:529 #3: ffff8880589a2ad0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x610 drivers/net/wireguard/noise.c:530 2 locks held by syz-executor/20008: 4 locks held by kworker/u8:17/20010: 2 locks held by syz-executor/20023: 2 locks held by dhcpcd/20036: #0: ffff888077e68260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888077e68260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf50 net/packet/af_packet.c:3204 #1: ffffffff8e7f1028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by syz-executor/20037: ============================================= NMI backtrace for cpu 1 CPU: 1 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 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 19958 Comm: kworker/u8:8 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:lock_acquire kernel/locking/lockdep.c:5868 [inline] RIP: 0010:lock_acquire+0x181/0x370 kernel/locking/lockdep.c:5825 Code: 0f 85 98 00 00 00 9c 8f 04 24 fa 48 c7 c7 93 0d 01 8e e8 72 85 a5 09 45 89 e8 44 89 e1 89 da 65 ff 05 0b 74 26 12 4c 8b 14 24 <44> 89 f6 48 89 ef 41 81 e2 00 02 00 00 4c 89 14 24 4d 89 d1 6a 00 RSP: 0018:ffffc90000006eb0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8e010d93 RDI: ffffffff8c1c3500 RBP: ffffffff8e7e54e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000246 R11: 000000000001761a R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124376000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005577ff493660 CR3: 000000000e596000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905 skb_clone+0x190/0x400 net/core/skbuff.c:2107 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x35c/0x650 net/bridge/br_forward.c:250 br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1161 br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183 br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:509 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6089 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6200 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6315 process_backlog+0x37a/0x1580 net/core/dev.c:6666 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7730 napi_poll net/core/dev.c:7793 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7950 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x21c/0x3d0 net/batman-adv/translation-table.c:1320 batadv_tt_purge+0x8b/0xbd0 net/batman-adv/translation-table.c:3514 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245