INFO: task kworker/u8:3:55 blocked for more than 145 seconds. Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:24248 pid:55 tgid:55 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by kthreadd/2: 3 locks held by kworker/0:0/9: 4 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 4 locks held by kworker/u8:1/13: 2 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e3bfc00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bfc00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bfc00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 3 locks held by kworker/u8:2/36: 5 locks held by kworker/u9:0/53: #0: ffff88803737a148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000bf7d18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88807f408d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff88807f408078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1269 3 locks held by kworker/u8:3/55: #0: ffff88801b481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000121fd18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90125ca8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 3 locks held by kworker/u8:4/64: 2 locks held by kworker/1:2/872: 3 locks held by kworker/0:2/972: 3 locks held by kworker/u8:5/1090: 3 locks held by kworker/u8:6/1121: 4 locks held by kworker/u8:7/1150: 2 locks held by kworker/u8:8/1163: 3 locks held by kworker/u8:9/2992: 3 locks held by kworker/R-ipv6_/3166: #0: ffff8880319a3148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000bf67cb0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90125ca8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90125ca8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4738 4 locks held by kworker/R-bat_e/3396: 5 locks held by kworker/u9:1/5127: #0: ffff88807c4eb948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90010157d18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888077b6cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff888077b6c078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1269 2 locks held by klogd/5175: 2 locks held by udevd/5186: 2 locks held by crond/5555: 2 locks held by getty/5573: #0: ffff888036be80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5799: 1 lock held by syz-executor/5809: 5 locks held by kworker/u9:2/5818: #0: ffff88802a289948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000463fd18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805a45cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff88805a45c078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1269 4 locks held by kworker/u9:4/5822: #0: ffff8880288d4948 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000466fd18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880794f0d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff8880794f0078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 1 lock held by syz-executor/5823: 6 locks held by kworker/u9:5/5825: #0: ffff888027956948 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000468fd18 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888024a78d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff888024a78078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] #4: ffffffff90393788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1269 #5: ffff888032e00338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1761 4 locks held by kworker/1:3/5833: 3 locks held by kworker/1:4/5863: 4 locks held by kworker/1:5/5864: 2 locks held by kworker/1:6/5865: 3 locks held by kworker/0:3/5866: 3 locks held by kworker/1:7/5867: 3 locks held by kworker/0:5/5895: 4 locks held by kworker/0:6/5896: 2 locks held by kworker/0:7/5907: 3 locks held by kworker/1:8/5912: #0: ffff88801b479d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000522fd18 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90125ca8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x83/0x1170 net/wireless/reg.c:2483 1 lock held by kworker/1:9/5916: 4 locks held by kworker/u8:10/6030: 4 locks held by kworker/u8:11/6033: 3 locks held by kworker/u8:12/6036: 4 locks held by kworker/u8:13/6037: 3 locks held by kworker/u8:14/6038: 2 locks held by syz.6.261/7030: 2 locks held by syz.5.262/7035: 3 locks held by kworker/u8:15/7049: 3 locks held by sed/7050: 4 locks held by kworker/u8:16/7051: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 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: 3396 Comm: kworker/R-bat_e Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:__sanitizer_cov_trace_switch+0x5d/0x90 kernel/kcov.c:352 Code: 00 31 db 4d 85 f6 74 1e 48 8b 74 dd 10 48 8b 4c 24 28 4c 89 e2 4c 89 ef 48 83 c3 01 e8 8c fd ff ff 49 39 de 75 e2 5b 5d 41 5c <41> 5d 41 5e e9 9a c6 b4 09 41 bd 07 00 00 00 48 83 f8 40 74 be 5b RSP: 0018:ffffc90000a082e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92000141061 RCX: ffffffff8a40a604 RDX: ffff88803285a440 RSI: 000000000000000a RDI: 0000000000000001 RBP: 0000000000000007 R08: 0000000000000001 R09: 000000000000000a R10: 0000000000000007 R11: 0000000000000000 R12: ffff888024f7c000 R13: 0000000000000001 R14: 0000000000000004 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124adf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f549cd81c78 CR3: 0000000052f7b000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_hook.constprop.0+0xd4/0x6b0 include/linux/netfilter.h:239 NF_HOOK include/linux/netfilter.h:312 [inline] br_pass_frame_up+0x307/0x490 net/bridge/br_input.c:70 br_handle_frame_finish+0xebb/0x1c20 net/bridge/br_input.c:226 br_nf_hook_thresh+0x304/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:314 [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:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0xad8/0x14a0 net/bridge/br_input.c:433 __netif_receive_skb_core.constprop.0+0xa26/0x4a00 net/core/dev.c:5773 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5885 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6000 process_backlog+0x442/0x15e0 net/core/dev.c:6352 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7510 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_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x25f/0xb80 net/batman-adv/translation-table.c:3510 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] rescuer_thread+0x620/0xea0 kernel/workqueue.c:3496 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245