INFO: task kworker/1:4:5911 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:24664 pid:5911 tgid:5911 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient crda_timeout_work Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 crda_timeout_work+0x15/0x50 net/wireless/reg.c:541 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.3.36:6128 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.36 state:D stack:27080 pid:6128 tgid:6118 ppid:5867 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 tty_set_ldisc+0x8b/0x780 drivers/tty/tty_ldisc.c:528 tiocsetd drivers/tty/tty_io.c:2429 [inline] tty_ioctl+0xc2e/0x1680 drivers/tty/tty_io.c:2728 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd02e58eec9 RSP: 002b:00007fd02f44c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd02e7e6090 RCX: 00007fd02e58eec9 RDX: 0000000000000000 RSI: 0000000000005423 RDI: 0000000000000005 RBP: 00007fd02e611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd02e7e6128 R14: 00007fd02e7e6090 R15: 00007ffedfac1728 INFO: task syz.3.36:6129 blocked for more than 142 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.36 state:D stack:27080 pid:6129 tgid:6118 ppid:5867 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 tty_fasync+0x5d/0xe0 drivers/tty/tty_io.c:2250 __fput+0x96b/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x41c/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd02e58eec9 RSP: 002b:00007fd02f42b038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fd02e7e6180 RCX: 00007fd02e58eec9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000002 RBP: 00007fd02e611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd02e7e6218 R14: 00007fd02e7e6180 R15: 00007ffedfac1728 Showing all locks held in the system: 1 lock held by kthreadd/2: 2 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: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: 1 lock held by khugepaged/38: #0: ffffffff8e6f3068 (lock#3){+.+.}-{4:4}, at: __lru_add_drain_all+0x69/0x6f0 mm/swap.c:837 3 locks held by kworker/u8:3/48: 7 locks held by kworker/u9:0/50: #0: ffff8880291a0148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000ba7d10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888078600dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff8880786000b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb20 net/bluetooth/hci_sync.c:5677 #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2100 [inline] #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1313 #5: ffff88801f6f0b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 #6: ffffffff8e5ccab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/u8:4/63: 5 locks held by kworker/u8:5/1039: 4 locks held by kworker/u8:6/2974: #0: ffff88801c6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000b287d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90372a50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658 #3: ffffffff90388d48 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x83/0x350 net/mpls/af_mpls.c:2706 2 locks held by kworker/u8:7/2978: #0: ffff88801b889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000b507d10 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 3 locks held by kworker/R-ipv6_/3201: #0: ffff888030e2b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000b707ca8 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90388d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90388d48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/R-bat_e/3425: 2 locks held by klogd/5222: 4 locks held by udevd/5233: 1 lock held by dhcpcd/5527: 5 locks held by dhcpcd/5528: 2 locks held by getty/5624: #0: ffff888034e0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000362b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz-executor/5851: 2 locks held by syz-executor/5861: 5 locks held by kworker/u9:2/5864: #0: ffff888028c57948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000415fd10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88802963cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff88802963c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb20 net/bluetooth/hci_sync.c:5677 #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2100 [inline] #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1313 3 locks held by syz-executor/5868: 5 locks held by kworker/u9:3/5870: #0: ffff8880291a1948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000419fd10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888078604dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff8880786040b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb20 net/bluetooth/hci_sync.c:5677 #4: ffffffff8e5ccab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 5 locks held by kworker/u9:4/5873: #0: ffff8880291a6948 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900041dfd10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff8880785d0dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff8880785d00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb20 net/bluetooth/hci_sync.c:5677 #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2100 [inline] #4: ffffffff905f13a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1313 3 locks held by kworker/1:4/5911: #0: ffff88801b882148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900043efd10 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90388d48 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x15/0x50 net/wireless/reg.c:541 3 locks held by kworker/1:5/5918: #0: ffff88801b882148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000445fd10 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90388d48 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x83/0x1180 net/wireless/reg.c:2483 2 locks held by kworker/1:6/5931: 3 locks held by kworker/0:3/5932: 2 locks held by kworker/1:7/5950: 2 locks held by syz.2.27/6076: 3 locks held by syz.2.29/6100: 2 locks held by syz.2.33/6119: 5 locks held by syz.3.36/6120: 1 lock held by syz.3.36/6128: #0: ffff8880794041c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_set_ldisc+0x8b/0x780 drivers/tty/tty_ldisc.c:528 1 lock held by syz.3.36/6129: #0: ffff8880794041c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_fasync+0x5d/0xe0 drivers/tty/tty_io.c:2250 3 locks held by modprobe/6134: 3 locks held by kworker/u8:8/6139: 3 locks held by kworker/u8:9/6140: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 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: 3425 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_dat_purge RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217 Code: 24 65 48 8b 15 98 68 1b 12 65 8b 05 a9 68 1b 12 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 <8b> 82 3c 16 00 00 85 c0 74 2b 8b 82 18 16 00 00 83 f8 02 75 20 48 RSP: 0018:ffffc900000070c0 EFLAGS: 00000246 RAX: 0000000080000101 RBX: 0000000000000002 RCX: 0000000000000002 RDX: ffff8880317fda00 RSI: ffffffff8a6d3025 RDI: ffffffff8c163780 RBP: ffffffff8a3abbf0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90abad97 R11: 0000000000002c10 R12: ffffc90000007180 R13: ffff88809c01d610 R14: ffffffff8a6d2f10 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd92f33fb8 CR3: 000000007a972000 CR4: 00000000003526f0 Call Trace: ip_sabotage_in+0x115/0x290 net/bridge/br_netfilter_hooks.c:984 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ipv6_rcv+0xa4/0x650 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5991 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6104 netif_receive_skb_internal net/core/dev.c:6190 [inline] netif_receive_skb+0x137/0x7b0 net/core/dev.c:6249 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+0xf5a/0x1ca0 net/bridge/br_input.c:227 br_nf_hook_thresh+0x304/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 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:283 [inline] br_handle_frame+0xad5/0x14b0 net/bridge/br_input.c:434 __netif_receive_skb_core.constprop.0+0xa25/0x48c0 net/core/dev.c:5878 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5989 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6104 process_backlog+0x442/0x15e0 net/core/dev.c:6456 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7506 napi_poll net/core/dev.c:7569 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge.part.0+0x279/0x3a0 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+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] rescuer_thread+0x620/0xea0 kernel/workqueue.c:3496 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245