INFO: task syz.6.2662:24490 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.2662 state:D stack:25776 pid:24490 tgid:24485 ppid:16174 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290 fs/nfsd/nfsctl.c:1477 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1027 netlink_dump+0x6e4/0xe90 net/netlink/af_netlink.c:2325 __netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440 genl_family_rcv_msg_dumpit+0x1e7/0x2c0 net/netlink/genetlink.c:1076 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline] genl_rcv_msg+0x5da/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] ____sys_sendmsg+0x577/0x880 net/socket.c:2610 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2664 __sys_sendmsg net/socket.c:2696 [inline] __do_sys_sendmsg net/socket.c:2701 [inline] __se_sys_sendmsg net/socket.c:2699 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2699 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd926d8f749 RSP: 002b:00007fd927ca4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd926fe6090 RCX: 00007fd926d8f749 RDX: 0000000000000800 RSI: 0000200000000180 RDI: 0000000000000008 RBP: 00007fd926e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd926fe6128 R14: 00007fd926fe6090 R15: 00007ffcb2033438 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/35: #0: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff88807d270788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline] #2: ffff88807d270788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x450 net/wireless/core.c:424 2 locks held by getty/5584: #0: ffff88814d7b70a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz.4.1970/17912: #0: ffffffff8f794230 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e635308 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880 2 locks held by syz.0.2604/23931: #0: ffff88807cd6e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807cd6e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807cd6e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e635308 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:575 3 locks held by syz.6.2662/24490: #0: ffffffff8f794230 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff8880345356f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #2: ffffffff8e635308 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290 fs/nfsd/nfsctl.c:1477 1 lock held by syz.3.3145/29351: #0: ffff88807cd6e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88807cd6e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz-executor/29823: #0: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 2 locks held by kworker/0:9/30446: 2 locks held by kworker/0:12/30529: 1 lock held by syz.1.3353/31156: #0: ffffffff8e344d00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5877 Comm: kworker/0:3 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker RIP: 0010:check_preemption_disabled+0x12/0x120 lib/smp_processor_id.c:13 Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 be e1 5c 07 <48> 89 44 24 08 65 8b 05 c6 e1 5c 07 65 8b 0d bb e1 5c 07 f7 c1 ff RSP: 0018:ffffc90000006e88 EFLAGS: 00000286 RAX: 57258eddc853b000 RBX: 0000000000000000 RCX: 0000000000000101 RDX: ffff88807bb51e80 RSI: ffffffff8be247c0 RDI: ffffffff8be24780 RBP: 0000000000000001 R08: ffffffff8a187bdd R09: ffffffff8e33f2e0 R10: 0000000000000003 R11: 0000000000000100 R12: dffffc0000000000 R13: ffff888027e76780 R14: ffffffff8a187bdd R15: ffff888031e11000 FS: 0000000000000000(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560aa016ea38 CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: rcu_lockdep_current_cpu_online+0x37/0x120 kernel/rcu/tree.c:4028 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 __in6_dev_get include/net/addrconf.h:347 [inline] ip6_dst_mtu_maybe_forward include/net/ip6_route.h:340 [inline] ip6_mtu+0x1b9/0x490 net/ipv6/route.c:3266 __ip6_finish_output net/ipv6/ip6_output.c:201 [inline] ip6_finish_output+0x12a/0x4e0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 synproxy_send_tcp_ipv6+0x543/0x700 net/netfilter/nf_synproxy_core.c:851 synproxy_send_client_synack_ipv6+0x80e/0xca0 net/netfilter/nf_synproxy_core.c:897 nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6138 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6251 process_backlog+0x622/0x1500 net/core/dev.c:6603 __napi_poll+0xae/0x320 net/core/dev.c:7667 napi_poll net/core/dev.c:7730 [inline] net_rx_action+0x672/0xe50 net/core/dev.c:7882 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:480 blake2s_compress+0xe0/0x1e30 lib/crypto/x86/blake2s.h:42 blake2s_final+0x116/0x260 lib/crypto/blake2s.c:142 hmac+0x1c6/0x330 drivers/net/wireguard/noise.c:325 kdf drivers/net/wireguard/noise.c:367 [inline] message_ephemeral+0x1e2/0x280 drivers/net/wireguard/noise.c:493 wg_noise_handshake_consume_initiation+0x1cb/0x900 drivers/net/wireguard/noise.c:605 wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline] wg_packet_handshake_receive_worker+0x5ee/0xfc0 drivers/net/wireguard/receive.c:213 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246