INFO: task kworker/u8:4:74 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00114-g327579671a9b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:23512 pid:74 tgid:74 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:7910 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00114-g327579671a9b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:25864 pid:7910 tgid:7910 ppid:7892 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 ip_tunnel_init_net+0x21d/0x7d0 net/ipv4/ip_tunnel.c:1160 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x1ff/0x510 net/core/net_namespace.c:442 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 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: 0033:0x7f55b89901a7 RSP: 002b:00007ffc830e3c58 EFLAGS: 00000206 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f55b8bb5f40 RCX: 00007f55b89901a7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f55b8bb6738 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kthreadd/2: 6 locks held by kworker/u8:0/12: 3 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 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: ffff88805449e948 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000bb7d10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888022f50dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff888022f500b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb10 net/bluetooth/hci_sync.c:5670 #4: ffffffff905d0028 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] #4: ffffffff905d0028 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1275 #5: ffff888057439338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 #6: ffffffff8e5d03f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 3 locks held by kworker/u8:4/74: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000214fd10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 3 locks held by kworker/u8:5/1029: 3 locks held by kworker/u8:6/1103: 3 locks held by kworker/u8:7/3001: 2 locks held by kworker/1:2/3090: 3 locks held by kworker/R-ipv6_/3180: #0: ffff888031d7b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000c627ca8 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4733 3 locks held by kworker/R-bat_e/3410: 3 locks held by kworker/u8:8/3686: 5 locks held by kworker/u9:1/5152: #0: ffff88807a5e1948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900103f7d10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880260c8dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 #3: ffff8880260c80b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x13f/0xb10 net/bluetooth/hci_sync.c:5670 #4: ffffffff905d0028 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] #4: ffffffff905d0028 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1275 1 lock held by syslogd/5184: #0: ffff888022307d08 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1327 1 lock held by klogd/5191: #0: ffff888031709e48 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1327 2 locks held by udevd/5202: 1 lock held by dhcpcd/5496: #0: ffff88807e2f4088 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1327 5 locks held by dhcpcd/5497: 1 lock held by crond/5571: 2 locks held by getty/5589: #0: ffff88803294e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5815: 3 locks held by kworker/1:4/5900: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003447d10 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by kworker/0:6/5913: 2 locks held by kworker/0:7/5940: 2 locks held by kworker/1:5/5956: 3 locks held by kworker/u8:9/6346: 3 locks held by kworker/u8:10/6596: 2 locks held by kworker/1:8/7647: 1 lock held by syz.0.536/7701: #0: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396 3 locks held by syz-executor/7753: 3 locks held by syz.4.582/7860: 2 locks held by syz-executor/7885: #0: ffffffff903488d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 #1: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11218 3 locks held by kworker/u8:11/7906: 2 locks held by syz-executor/7910: #0: ffffffff903488d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 #1: ffffffff9035e928 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21d/0x7d0 net/ipv4/ip_tunnel.c:1160 1 lock held by syz-executor/7913: 4 locks held by syz-executor/7925: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00114-g327579671a9b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: 3410 Comm: kworker/R-bat_e Not tainted 6.16.0-rc7-syzkaller-00114-g327579671a9b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:__sanitizer_cov_trace_switch+0x4b/0x90 kernel/kcov.c:350 Code: 08 74 5b 48 83 f8 10 75 2f 41 bd 03 00 00 00 4c 8b 75 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 RSP: 0018:ffffc900000070f8 EFLAGS: 00000202 RAX: 0000000000000008 RBX: 0000000000000000 RCX: ffffffff8a637b79 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff8cf81520 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000002 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124720000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7623f07000 CR3: 0000000033a29000 CR4: 00000000003526f0 Call Trace: nf_bridge_update_protocol net/bridge/br_netfilter_hooks.c:258 [inline] br_nf_forward_finish+0x559/0xba0 net/bridge/br_netfilter_hooks.c:659 NF_HOOK include/linux/netfilter.h:317 [inline] NF_HOOK include/linux/netfilter.h:311 [inline] br_nf_forward_ip.part.0+0x609/0x810 net/bridge/br_netfilter_hooks.c:719 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:679 [inline] br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:776 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook+0x45e/0x780 include/linux/netfilter.h:272 NF_HOOK include/linux/netfilter.h:315 [inline] __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x39c/0x650 net/bridge/br_forward.c:249 br_handle_frame_finish+0xf2d/0x1ca0 net/bridge/br_input.c:221 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:317 [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:157 [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+0xa23/0x4a00 net/core/dev.c:5863 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5975 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090 process_backlog+0x442/0x15e0 net/core/dev.c:6442 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605 handle_softirqs+0x219/0x8e0 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_local_purge+0x21c/0x3c0 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x8b/0xb80 net/batman-adv/translation-table.c:3509 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] rescuer_thread+0x620/0xea0 kernel/workqueue.c:3498 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245