INFO: task kworker/0:6:5957 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/0:6 state:D stack:21816 pid:5957 tgid:5957 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient reg_check_chans_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 class_wiphy_constructor include/net/cfg80211.h:6441 [inline] reg_leave_invalid_chans net/wireless/reg.c:2450 [inline] reg_check_chans_work+0x12f/0x11d0 net/wireless/reg.c:2465 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: 1 lock held by khungtaskd/31: #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by kcompactd1/35: 3 locks held by kworker/R-ipv6_/3179: #0: ffff8880346a3148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000d75fc70 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90614628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90614628 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4738 1 lock held by klogd/5167: 4 locks held by udevd/5178: 2 locks held by dhcpcd/5472: 5 locks held by dhcpcd/5473: 2 locks held by getty/5566: #0: ffff888039d1b0a0 (&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 4 locks held by syz-executor/5803: 2 locks held by syz-executor/5804: 4 locks held by kworker/0:6/5957: #0: ffff88813fe65d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900025bfd08 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90614628 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x11d0 net/wireless/reg.c:2462 #3: ffff888076d40788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6441 [inline] #3: ffff888076d40788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2450 [inline] #3: ffff888076d40788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x12f/0x11d0 net/wireless/reg.c:2465 3 locks held by kworker/0:7/5958: #0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900025afd08 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff90614628 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:22/11024: 2 locks held by kworker/u8:24/11026: #0: ffff88801f78f948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9001d307d08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 5 locks held by kworker/u8:26/11028: 5 locks held by syz-executor/12766: 3 locks held by syz.0.1930/13079: #0: ffff88807ef64ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff88807ef640c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356 #2: ffffffff8e7f3478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 2 locks held by syz.4.2688/15839: #0: ffffffff905fbdd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 #1: ffffffff90614628 (rtnl_mutex){+.+.}-{4:4}, at: ipmr_net_exit_batch+0x15/0xa0 net/ipv4/ipmr.c:3276 5 locks held by syz-executor/15861: ============================================= 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 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11025 Comm: kworker/u8:23 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: kvfree_rcu_reclaim kfree_rcu_work RIP: 0010:rcu_is_watching+0x83/0xc0 kernel/rcu/tree.c:755 Code: c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 83 e0 01 65 ff 0d 80 08 21 12 74 07 5b <5d> c3 cc cc cc cc e8 f2 01 89 ff 5b 5d e9 1b 04 a7 09 48 89 df e8 RSP: 0018:ffffc9001d2f7a10 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8c1b1e20 RDI: ffffffff8e12c8e0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff90d9da17 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124338000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa1ca6fbff8 CR3: 00000000371b5000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x317/0x380 kernel/locking/lockdep.c:5831 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:890 debug_rcu_head_unqueue kernel/rcu/rcu.h:248 [inline] kvfree_rcu_list+0x44/0xc0 mm/slab_common.c:1535 kfree_rcu_work+0x16d/0x1a0 mm/slab_common.c:1591 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