INFO: task kworker/u4:1:12 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-07749-g28eb75e178d3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:21424 pid:12 tgid:12 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 3 locks held by kworker/0:1/9: #0: ffff88801ac75948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac75948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900003b7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900003b7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x99/0xfd0 net/wireless/reg.c:2480 3 locks held by kworker/u4:1/12: #0: ffff88803f43f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88803f43f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900003e7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900003e7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 1 lock held by khungtaskd/26: #0: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 1 lock held by kcompactd1/30: 4 locks held by kworker/u4:3/46: #0: ffff88801baf3148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baf3148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000060fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000060fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fccc150 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586 #3: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415 2 locks held by kworker/u4:4/55: 2 locks held by kworker/u4:8/1057: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900022cfd00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900022cfd00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by getty/5121: #0: ffff8880008f90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000039b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5436: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd04/0x24f0 net/core/rtnetlink.c:4000 #1: ffff888056ea54e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x22d/0x420 drivers/net/wireguard/device.c:50 1 lock held by syz-executor/5438: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 3 locks held by syz-executor/5439: #0: ffffffff8fd3f810 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8fd3f6c8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fd3f6c8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fd3f6c8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x121/0xec0 net/netlink/genetlink.c:1209 #2: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: wiphy_register+0x1a3f/0x27b0 net/wireless/core.c:1009 3 locks held by syz-executor/5455: #0: ffff888035990d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888035990d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698 #1: ffff888035990078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5200 #2: ffffffff8e941df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e941df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u4:12/5606: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000ca6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000ca6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 3 locks held by kworker/0:13/5623: #0: ffff88801ac74948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac74948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000272fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000272fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8e941df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e941df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz-executor/5626: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5630: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5631: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5638: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5643: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5655: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5672: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5674: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5678: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5684: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5688: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5699: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz-executor/5708: #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd8c88 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted 6.12.0-syzkaller-07749-g28eb75e178d3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244