INFO: task dhcpcd:5482 blocked for more than 144 seconds. Tainted: G U L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:26376 pid:5482 tgid:5482 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 vlan_ioctl_handler+0xcf/0xa70 net/8021q/vlan.c:579 sock_ioctl+0x5e9/0x6b0 net/socket.c:1339 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06d08e9378 RSP: 002b:00007ffd107bd378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000561fd9d57160 RCX: 00007f06d08e9378 RDX: 00007ffd107bd380 RSI: 0000000000008982 RDI: 000000000000000f RBP: 00007ffd107bd380 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 0000561fd9edfb50 R14: 00007ffd107cd790 R15: 0000561fd9d57160 INFO: task kworker/u8:32:7389 blocked for more than 144 seconds. Tainted: G U L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:32 state:D stack:23576 pid:7389 tgid:7389 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4199 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:25236 blocked for more than 144 seconds. Tainted: G U L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24776 pid:25236 tgid:25236 ppid:25229 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x4aa/0x520 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f116595c84e RSP: 002b:00007fffb4cb5c28 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055556445a500 RCX: 00007f116595c84e RDX: 0000000000000028 RSI: 00007f1166744670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fffb4cb5ca4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f1166744670 R15: 0000000000000000 INFO: task syz.2.3989:25401 blocked for more than 144 seconds. Tainted: G U L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3989 state:D stack:27688 pid:25401 tgid:25374 ppid:16405 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1146 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:446 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:581 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x455/0xab0 kernel/fork.c:3174 __do_sys_unshare kernel/fork.c:3245 [inline] __se_sys_unshare kernel/fork.c:3243 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3243 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f88f7d9bf79 RSP: 002b:00007f88f5fd5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f88f8016180 RCX: 00007f88f7d9bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080 RBP: 00007f88f7e327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f88f8016218 R14: 00007f88f8016180 R15: 00007ffe7a1396f8 Showing all locks held in the system: 1 lock held by kthreadd/2: 3 locks held by kworker/0:1/10: #0: ffff88813fe17548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc900000f7d08 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e5e7060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e5e7060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e5e7060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by kswapd0/85: 3 locks held by kworker/0:2/119: #0: ffff88813fe16148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc90002dd7d08 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x10e0 net/wireless/reg.c:2464 3 locks held by kworker/u8:7/3452: 1 lock held by klogd/5177: 3 locks held by udevd/5188: 2 locks held by dhcpcd/5482: #0: ffffffff903d2008 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5ca/0x6b0 net/socket.c:1337 #1: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xcf/0xa70 net/8021q/vlan.c:579 3 locks held by crond/5561: 2 locks held by getty/5581: #0: ffff8880375a90a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 4 locks held by sshd-session/5804: 3 locks held by syz-executor/5805: 3 locks held by kworker/0:6/5914: #0: ffff88813fe17548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc900048b7d08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff8e5f2b40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 4 locks held by kworker/u8:18/6716: #0: ffff88801c2de948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc90004a87d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff903e9470 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675 #3: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1b/0x250 drivers/net/wireguard/device.c:419 4 locks held by kworker/u8:20/6718: 3 locks held by kworker/u8:22/6720: 3 locks held by kworker/u8:23/6721: 3 locks held by kworker/u8:28/6726: 3 locks held by kworker/u8:32/7389: #0: ffff8880326ea948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc90004bd7d08 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4199 2 locks held by syz-executor/16746: 3 locks held by kworker/u8:2/17445: 3 locks held by kworker/u8:5/17449: 4 locks held by kworker/u8:6/17450: 4 locks held by kworker/u8:9/17453: 3 locks held by kworker/u8:10/17460: 3 locks held by kworker/u8:16/19967: 3 locks held by kworker/u8:17/19968: 3 locks held by kworker/u8:21/19970: 8 locks held by kworker/u8:27/19976: 2 locks held by kworker/u8:30/19978: 4 locks held by kworker/u8:31/19979: 4 locks held by kworker/u8:37/21214: 3 locks held by kworker/u8:38/21215: 4 locks held by kworker/u8:40/21217: 4 locks held by kworker/u8:41/21218: 4 locks held by kworker/u8:43/21220: 7 locks held by kworker/u9:1/24558: #0: ffff888026419148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc90004787d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffff88804d5acec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331 #3: ffff88804d5ac0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5734 #4: ffffffff90699ce8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline] #4: ffffffff90699ce8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342 #5: ffff88802c735af8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x770 net/bluetooth/l2cap_core.c:1755 #6: ffffffff8e5f2c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by syz-executor/25236: #0: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 2 locks held by syz.2.3989/25401: #0: ffffffff903e9470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90401d68 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1146 6 locks held by syz.2.3989/25405: 2 locks held by syz.0.3991/25383: 2 locks held by syz.0.3991/25389: 2 locks held by syz.3.3992/25384: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245