INFO: task syz.1.380:7423 blocked for more than 158 seconds. Not tainted 6.14.0-rc5-syzkaller-00218-g2a520073e74f #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.380 state:D stack:25760 pid:7423 tgid:7423 ppid:5830 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 tun_detach drivers/net/tun.c:698 [inline] tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 __fput+0x3eb/0x9f0 fs/file_table.c:464 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb5021bfa25 RSP: 002b:00007fb503078f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fb5023a5fa0 RCX: 00007fb5021bfa25 RDX: 00007fb503078fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fb50220e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb5023a5fa0 R15: 00007ffd15283158 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8eb3e7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8eb3e7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 1 lock held by khungtaskd/31: #0: ffffffff8eb39320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb39320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb39320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/0:2/970: 2 locks held by getty/5590: #0: ffff888030c570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:4/5888: 7 locks held by kworker/1:7/5928: 3 locks held by kworker/0:8/5931: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000460fc60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000460fc60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:9/5940: #0: ffff8880306db148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880306db148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000463fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000463fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #2: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730 2 locks held by kworker/u8:11/6055: 2 locks held by kworker/u8:13/6346: 4 locks held by kworker/u8:14/6925: #0: ffff88801beee148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801beee148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003617c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003617c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec93d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606 #3: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415 3 locks held by kworker/u8:16/6990: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc900035b7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900035b7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 1 lock held by syz.1.380/7423: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz-executor/7442: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz.3.515/8015: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 2 locks held by kworker/1:8/8219: 2 locks held by syz-executor/10096: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 #1: ffffffff8eb3e7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #1: ffffffff8eb3e7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:996 1 lock held by syz-executor/10966: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10967: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10969: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10974: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10975: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 2 locks held by syz-executor/10979: #0: ffffffff8fec93d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:512 #1: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x29a/0x7e0 net/ipv4/ip_tunnel.c:1159 1 lock held by syz-executor/10984: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10986: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10993: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10994: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10995: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 1 lock held by syz-executor/10996: #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5c08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc5-syzkaller-00218-g2a520073e74f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8219 Comm: kworker/1:8 Not tainted 6.14.0-rc5-syzkaller-00218-g2a520073e74f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker RIP: 0010:cake_dequeue+0x4a5/0x4be0 net/sched/sch_cake.c:2008 Code: c5 84 98 01 00 4d 89 ee 49 c1 ee 03 43 0f b6 04 26 84 c0 0f 85 28 02 00 00 45 8b 65 00 31 ff 44 89 e6 e8 4e 26 c1 f7 45 85 e4 <44> 89 7c 24 30 78 79 48 8b 5c 24 48 48 8d bb 2e 98 01 00 48 89 f8 RSP: 0018:ffffc90003fded20 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000001260002 RCX: ffff88802fe8bc00 RDX: ffff88802fe8bc00 RSI: 0000000000000100 RDI: 0000000000000000 RBP: ffffc90003fdef80 R08: ffffffff8a00bce2 R09: 1ffffffff28a9542 R10: dffffc0000000000 R11: ffffffff81618020 R12: 0000000000000100 R13: ffff888043b4ca24 R14: 1ffff11008769944 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056345c05b088 CR3: 000000000e938000 CR4: 0000000000350ef0 Call Trace: dequeue_skb net/sched/sch_generic.c:293 [inline] qdisc_restart net/sched/sch_generic.c:398 [inline] __qdisc_run+0x274/0x2180 net/sched/sch_generic.c:416 __dev_xmit_skb net/core/dev.c:4108 [inline] __dev_queue_xmit+0x10dd/0x3f50 net/core/dev.c:4615 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0x127d/0x17c0 net/ipv6/ip6_output.c:141 ip6_finish_output+0x41e/0x840 net/ipv6/ip6_output.c:226 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline] udp_tunnel6_xmit_skb+0x61d/0xa70 net/ipv6/ip6_udp_tunnel.c:111 send6+0x6da/0xaf0 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0x115/0x1d0 drivers/net/wireguard/socket.c:178 wg_packet_send_handshake_response+0x198/0x2e0 drivers/net/wireguard/send.c:103 wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline] wg_packet_handshake_receive_worker+0x5e6/0xf50 drivers/net/wireguard/receive.c:213 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244