INFO: task kworker/1:3:5851 blocked for more than 158 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:24712 pid:5851 tgid:5851 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient crda_timeout_work Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 crda_timeout_work+0x16/0x70 net/wireless/reg.c:540 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 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: 2 locks held by kthreadd/2: 4 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 3 locks held by kworker/u8:1/13: 2 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 6 locks held by kworker/R-write/33: 3 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:3/49: 7 locks held by kworker/u9:0/51: #0: ffff88807a9c6148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90000bb7d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88803567cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff88803567c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744 #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342 #5: ffff88807e02db00 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777 #6: ffffffff8e7f32b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/u8:4/67: 3 locks held by kworker/u8:5/135: 4 locks held by kworker/u8:6/148: 3 locks held by kworker/u8:7/1099: 4 locks held by kworker/u8:8/1140: 3 locks held by kworker/u8:9/1151: 2 locks held by kworker/1:2/3097: 3 locks held by kworker/R-ipv6_/3184: #0: ffff888032150148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000dd2fc70 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90616868 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90616868 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4738 4 locks held by kworker/R-bat_e/3409: 5 locks held by kworker/u9:1/5144: #0: ffff888078f77148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90006697d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff888033b8cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff888033b8c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744 #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342 1 lock held by klogd/5183: 3 locks held by udevd/5194: 2 locks held by dhcpcd/5488: 2 locks held by crond/5566: 2 locks held by getty/5580: #0: ffff88803684b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5810: 2 locks held by syz-executor/5825: 5 locks held by kworker/u9:4/5829: #0: ffff888078f72148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90004597d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88807e248ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff88807e2480c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744 #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff908afb48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342 1 lock held by syz-executor/5833: 5 locks held by kworker/u9:5/5835: #0: ffff88807e694148 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900045d7d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff8880340a8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff8880340a80c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744 #4: ffffffff8e7f32b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 3 locks held by kworker/1:3/5851: #0: ffff88813fe61d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90004677d08 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90616868 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x16/0x70 net/wireless/reg.c:540 2 locks held by kworker/1:4/5852: 2 locks held by kworker/0:5/5888: 3 locks held by kworker/1:5/5910: #0: ffff88813fe61d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90004c87d08 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90616868 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x11d0 net/wireless/reg.c:2462 3 locks held by syz.1.10/5958: 2 locks held by syz.2.13/5967: 4 locks held by syz.3.14/5977: 1 lock held by kworker/u8:10/5980: ============================================= 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 03/18/2026 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:161 [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:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3409 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:__lock_acquire+0xe/0x2630 kernel/locking/lockdep.c:5090 Code: e5 8d 67 48 0f b9 3a eb ba 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 55 53 48 83 ec 70 <8b> 1d 50 df f5 0e 65 4c 8b 25 6c a3 29 12 4c 89 64 24 68 4c 8b a4 RSP: 0018:ffffc90000a07970 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e7e7760 RBP: ffffffff8e7e7760 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000200 R11: 0000000000096742 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124441000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe5c34265c CR3: 000000007dcb6000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd1/0x1ea0 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 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x124/0x6a0 mm/slub.c:6295 __skb_ext_put+0x102/0x2f0 net/core/skbuff.c:7252 skb_ext_reset include/linux/skbuff.h:5090 [inline] skb_ext_reset include/linux/skbuff.h:5087 [inline] skb_release_head_state+0x2c8/0x400 net/core/skbuff.c:1195 skb_release_all net/core/skbuff.c:1201 [inline] __kfree_skb net/core/skbuff.c:1217 [inline] sk_skb_reason_drop+0xc4/0x1b0 net/core/skbuff.c:1255 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ip6_mc_input+0x832/0xf50 net/ipv6/ip6_input.c:593 dst_input include/net/dst.h:480 [inline] ip6_rcv_finish+0x294/0x300 net/ipv6/ip6_input.c:79 ip_sabotage_in+0x21e/0x290 net/bridge/br_netfilter_hooks.c:990 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ipv6_rcv+0xa4/0x3d0 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6181 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6294 netif_receive_skb_internal net/core/dev.c:6380 [inline] netif_receive_skb+0x139/0x820 net/core/dev.c:6439 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70 br_handle_frame_finish+0xa74/0x1f60 net/bridge/br_input.c:235 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x769/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x90d/0x1550 net/bridge/br_netfilter_hooks.c:508 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+0x6c5/0x3550 net/core/dev.c:6068 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6179 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6294 process_backlog+0x37a/0x1580 net/core/dev.c:6645 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7709 napi_poll net/core/dev.c:7772 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7929 handle_softirqs+0x1eb/0x9e0 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:395 [inline] __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:185 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:166 [inline] batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:204 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3583 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245