INFO: task syz.0.10940:15059 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.10940 state:D stack:27200 pid:15059 tgid:15052 ppid:6913 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7334 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0x7f5/0x1550 kernel/locking/mutex.c:806 nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1693 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efd6ad9cdd9 RSP: 002b:00007efd6bc0c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007efd6b016090 RCX: 00007efd6ad9cdd9 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007efd6ae32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd6b016128 R14: 00007efd6b016090 R15: 00007fff00da8598 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5583: #0: ffff8880371e10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:11/4096: #0: ffff88813fe53140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88813fe53140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc90002db7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90002db7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 #2: ffff88809e464230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 3 locks held by kworker/u8:10/7324: #0: ffff88801ae94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88801ae94140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc90003567c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc90003567c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 #2: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:32/7336: #0: ffff88803230f940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline] #0: ffff88803230f940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371 #1: ffffc9000350fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline] #1: ffffc9000350fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371 #2: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4206 1 lock held by napi/wg2-0/8613: #0: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 2 locks held by syz.3.9191/8763: #0: ffffffff8fe3ddc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec88660 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1903 2 locks held by syz.0.10940/15059: #0: ffffffff8fe3ddc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec88660 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1693 1 lock held by syz-executor/18802: #0: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.7.12055/19222: #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 2 locks held by syz.7.12055/19248: #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff90325a78 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 4 locks held by syz.6.12058/19228: #0: ffffffff8fe3ddc8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff88807d23a128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #1: ffff88807d23a128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #1: ffff88807d23a128 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x34a/0x490 net/devlink/netlink.c:234 #2: ffff88807d239258 (&devlink->lock_key#23){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #2: ffff88807d239258 (&devlink->lock_key#23){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x360/0x490 net/devlink/netlink.c:234 #3: ffffffff8e9631f8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 1 lock held by syz.5.12064/19242: #0: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.8.12066/19252: #0: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 1 lock held by dhcpcd/19256: #0: ffff88805f67c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88805f67c260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3199 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfaa/0x1000 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 7350 Comm: kworker/u8:39 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x1978/0x2cf0 kernel/locking/lockdep.c:5237 Code: ce f6 a4 14 25 ff 0f 00 00 39 05 8f f6 a3 12 73 06 89 05 87 f6 a3 12 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 <48> 8b 00 4c 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 RSP: 0018:ffffc90003aaec60 EFLAGS: 00000006 RAX: ffffffff96e5faa8 RBX: 00000000000003fd RCX: 0000000000000340 RDX: ffffffff96dbad68 RSI: ffff88801e7bca50 RDI: 00000000000003fd RBP: 5fd5bd3aab5a52ff R08: ffffc90003aaec28 R09: 0000000000000020 R10: 0000000000000003 R11: ffffffff81a1e3d0 R12: ffffffff96e5fcd8 R13: ffffffff93edd4c0 R14: ffff88801e7bbd80 R15: 000000000000033f FS: 0000000000000000(0000) GS:ffff888125345000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd3de6b708 CR3: 00000000350f6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_get+0x45/0x220 kernel/time/timekeeping.c:965 clockevents_program_event+0x290/0x5f0 kernel/time/clockevents.c:360 hrtimer_rearm kernel/time/hrtimer.c:2039 [inline] __hrtimer_rearm_deferred+0x270/0x450 kernel/time/hrtimer.c:2059 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:513 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:550 [inline] irqentry_exit+0x6a0/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 a2 00 21 00 fb eb 44 e8 9a 00 21 00 e8 d5 b7 0e 0a 4d 85 f6 74 94 e8 8b 00 21 00 fb 48 c7 c7 40 f4 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 fb 17 RSP: 0018:ffffc90003aaf0a0 EFLAGS: 00000293 RAX: ffffffff81a45d65 RBX: ffffffff81a45bdf RCX: ffff88801e7bbd80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e94f440 RBP: ffffc90003aaf150 R08: ffffffff903215b7 R09: 1ffffffff20642b6 R10: dffffc0000000000 R11: fffffbfff20642b7 R12: 0000000000000000 R13: 0000000000000042 R14: 0000000000000200 R15: 1ffff92000755e18 _printk+0xdd/0x130 kernel/printk/printk.c:2504 gred_dequeue+0x4e6/0x6f0 net/sched/sch_gred.c:273 dequeue_skb net/sched/sch_generic.c:322 [inline] qdisc_restart net/sched/sch_generic.c:427 [inline] __qdisc_run+0x23f/0x1560 net/sched/sch_generic.c:445 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:4292 [inline] __dev_queue_xmit+0x1d26/0x3950 net/core/dev.c:4831 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 ip6tunnel_xmit include/net/ip6_tunnel.h:174 [inline] udp_tunnel6_xmit_skb+0x6e2/0xd70 net/ipv6/ip6_udp_tunnel.c:112 send6+0x5c0/0x910 drivers/net/wireguard/socket.c:151 wg_socket_send_skb_to_peer+0x111/0x1d0 drivers/net/wireguard/socket.c:177 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x203/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245