INFO: task kworker/R-wg-cr:5869 blocked for more than 153 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/R-wg-cr state:D stack:28552 pid:5869 tgid:5869 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: 0x0 (wg-crypt-wg0) Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 rescuer_thread+0x3aa/0xea0 kernel/workqueue.c:3480 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by kworker/R-rcu_g/4: 3 locks held by kworker/0:0/9: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900000e7d10 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by kworker/0:1/10: 2 locks held by kworker/u8:1/13: 1 lock held by kworker/R-mm_pe/14: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676 2 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/37: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000ad7d10 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: idle_cull_fn+0x99/0x460 kernel/workqueue.c:2958 2 locks held by kworker/1:1/44: 3 locks held by kworker/u8:5/1087: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000409fd10 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: idle_cull_fn+0x99/0x460 kernel/workqueue.c:2958 3 locks held by kworker/u8:6/1094: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000413fd10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 2 locks held by kworker/u8:7/1108: 2 locks held by getty/5603: #0: ffff88814d01b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5841: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 1 lock held by syz-executor/5843: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 1 lock held by syz-executor/5844: #0: ffffffff8e5cc680 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815 2 locks held by kworker/0:3/5845: 3 locks held by kworker/u9:2/5850: #0: ffff8880292cc948 ((wq_completion)hci1#9){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000428fd10 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88802a548dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open+0x22/0x90 net/bluetooth/hci_core.c:428 1 lock held by syz-executor/5852: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 1 lock held by kworker/R-wg-cr/5870: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5872: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5881: 1 lock held by kworker/R-wg-cr/5882: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5883: 1 lock held by kworker/R-wg-cr/5884: 1 lock held by kworker/R-wg-cr/5885: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5886: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5887: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676 1 lock held by kworker/R-wg-cr/5888: 1 lock held by kworker/R-wg-cr/5889: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5890: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5891: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by kworker/R-wg-cr/5892: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676 2 locks held by kworker/0:4/5899: 2 locks held by kworker/1:3/5907: 2 locks held by kworker/0:5/5914: 7 locks held by kworker/1:4/5928: 1 lock held by kworker/1:5/5929: #0: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676 2 locks held by kworker/0:6/5980: 2 locks held by kworker/0:7/5989: 4 locks held by kworker/u8:9/5993: #0: ffff88801c6f4148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000479fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff9036d010 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658 #3: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1b/0x230 drivers/net/wireguard/device.c:417 3 locks held by kworker/u8:10/6211: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900055e7d10 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e478488 (wq_pool_attach_mutex){+.+.}-{4:4}, at: idle_cull_fn+0x99/0x460 kernel/workqueue.c:2958 2 locks held by kworker/1:7/8112: 1 lock held by syz-executor/8158: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:979 1 lock held by syz-executor/8187: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:979 1 lock held by dhcpcd/8191: #0: ffff88805a2f7408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805a2f7408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:648 1 lock held by dhcpcd/8192: #0: ffff88805a37ee08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805a37ee08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:648 3 locks held by syz-executor/8200: #0: ffff88814d9f2428 (sb_writers#5){.+.+}-{0:0}, at: filename_create+0x10e/0x4a0 fs/namei.c:4132 #1: ffff88807ca103e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #1: ffff88807ca103e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1bb/0x4a0 fs/namei.c:4139 #2: ffff88814d9f6950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by dhcpcd/8201: #0: ffff888078778258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff888078778258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3251 #1: ffffffff8e5cc7b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by dhcpcd/8202: #0: ffff88807804e258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff88807804e258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3251 ============================================= 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 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: 5928 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: wg-crypt-wg1 wg_packet_tx_worker RIP: 0010:hash_64_generic include/linux/hash.h:78 [inline] RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3798 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline] RIP: 0010:__lock_acquire+0xbad/0x1ce0 kernel/locking/lockdep.c:5237 Code: 00 00 00 e9 f7 f9 ff ff 4c 89 e7 48 89 14 24 e8 29 a7 ff ff 4c 8b 04 24 48 b8 eb 83 b5 80 46 86 c8 61 49 0f af c0 48 c1 e8 2d <48> 89 04 24 4c 8d 3c c5 20 ba 1a 97 48 8b 04 c5 20 ba 1a 97 48 8d RSP: 0018:ffffc9000457f148 EFLAGS: 00000007 RAX: 0000000000021409 RBX: ffff888026975370 RCX: 00000000f8d1c0f0 RDX: 6c5a4f1893d84024 RSI: 000000004c09da94 RDI: ffff888026975488 RBP: 0000000000000000 R08: 6c5a4f1893d84024 R09: 0000000000000001 R10: 0000000000000007 R11: 0000000000000000 R12: ffff888026975488 R13: ffff888026974880 R14: 00000000690bad71 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881247b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fac4fae7d60 CR3: 0000000079732000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 local_lock_acquire include/linux/local_lock_internal.h:38 [inline] get_random_u16+0x102/0x7e0 drivers/char/random.c:553 cake_get_flow_quantum+0xd9/0x290 net/sched/sch_cake.c:687 cake_dequeue+0x1be7/0x4830 net/sched/sch_cake.c:2119 dequeue_skb net/sched/sch_generic.c:294 [inline] qdisc_restart net/sched/sch_generic.c:399 [inline] __qdisc_run+0x1bd/0x1bf0 net/sched/sch_generic.c:417 __dev_xmit_skb net/core/dev.c:4183 [inline] __dev_queue_xmit+0x2b43/0x4490 net/core/dev.c:4691 dev_queue_xmit include/linux/netdevice.h:3361 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141 __ip6_finish_output+0x3cd/0x1010 net/ipv6/ip6_output.c:215 ip6_finish_output net/ipv6/ip6_output.c:226 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x1ca/0x3e0 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:461 [inline] ip6_local_out+0xd1/0x4d0 net/ipv6/output_core.c:155 ip6tunnel_xmit include/net/ip6_tunnel.h:162 [inline] udp_tunnel6_xmit_skb+0x7f1/0xc50 net/ipv6/ip6_udp_tunnel.c:112 send6+0x4ba/0xd30 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0xf6/0x210 drivers/net/wireguard/socket.c:178 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1aa/0x810 drivers/net/wireguard/send.c:276 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236