INFO: task syz-executor:5844 blocked for more than 144 seconds. Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21640 pid:5844 tgid:5844 ppid:1 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 netdev_run_todo+0x327/0xea0 net/core/dev.c:11376 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x13c/0x1c0 drivers/net/tun.c:3396 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1da698d33c RSP: 002b:00007f1da6cdfd80 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007f1da698d33c RDX: 0000000000000030 RSI: 00007f1da6cdfe40 RDI: 00000000000000f9 RBP: 00007f1da6cdfdec R08: 0000000000000000 R09: 0079746972756365 R10: 00007f1da6b817e0 R11: 0000000000000246 R12: 0000000000000011 R13: 000055556f14d590 R14: 000000000001c854 R15: 00007f1da6cdfe40 Showing all locks held in the system: 5 locks held by kworker/R-netns/8: #0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc900000d7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900000d7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f503050 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:417 #4: ffff8880657514e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xb0/0x1d0 drivers/net/wireguard/device.c:422 4 locks held by kworker/0:1/10: #0: ffff888057006148 ((wq_completion)wg-kex-wg2#20){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888057006148 ((wq_completion)wg-kex-wg2#20){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc900000f7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900000f7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff8880639d1308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598 #3: ffff8880769fd278 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4de/0x900 drivers/net/wireguard/noise.c:632 3 locks held by kworker/u8:0/12: #0: ffff8880302a9148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880302a9148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000117bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/1:1/44: 2 locks held by getty/5591: #0: ffff8880310860a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5844: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 1 lock held by syz-executor/5845: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 7 locks held by kworker/1:3/5909: 3 locks held by kworker/1:4/5916: 3 locks held by kworker/1:5/5917: 2 locks held by kworker/1:7/5965: 2 locks held by kworker/1:8/6254: 1 lock held by syz-executor/6267: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 1 lock held by syz-executor/6269: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 1 lock held by syz-executor/6272: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 2 locks held by kworker/1:9/6284: 2 locks held by kworker/1:10/6309: 1 lock held by syz.6.90/6364: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 1 lock held by syz-executor/6369: #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.7.87/6379: #0: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 3 locks held by kworker/1:13/6388: 6 locks held by kworker/1:15/6396: 2 locks held by kworker/1:16/6397: 2 locks held by kworker/1:17/6405: 2 locks held by syz-executor/6412: #0: ffffffff8f503050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570 #1: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 2 locks held by syz-executor/6415: #0: ffffffff8f503050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570 #1: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 2 locks held by syz-executor/6417: #0: ffffffff8f503050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570 #1: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 1 lock held by syz.9.96/6421: #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/0:9/6429: #0: ffff888034ae5948 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888034ae5948 ((wq_completion)wg-kex-wg0#4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90003d0fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003d0fbc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888065020f08 (&cookie->lock){++++}-{4:4}, at: wg_cookie_add_mac_to_packet+0x3e/0x1a0 drivers/net/wireguard/cookie.c:162 3 locks held by kworker/u8:15/6431: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90003d5fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003d5fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f50fc48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 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: 6254 Comm: kworker/1:8 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:unwind_next_frame+0x10e/0x2390 include/linux/rcupdate.h:-1 Code: 3a 18 0e 00 75 1f c6 05 4b 3a 18 0e 01 48 c7 c7 a0 3c 88 8b be 4b 03 00 00 48 c7 c2 e0 3c 88 8b e8 57 c1 2b 00 4c 89 6c 24 70 <48> 89 5c 24 68 4d 8d 6e 50 4c 89 e8 48 c1 e8 03 48 89 44 24 38 80 RSP: 0018:ffffc90000a07c98 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff81acf66c RCX: e5a1f9b990237700 RDX: 0000000000000000 RSI: ffffffff8be28aa0 RDI: ffffffff8be28a60 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff81729af5 R10: ffffc90000a07db8 R11: ffffffff81acf6c0 R12: 1ffff92000140fad R13: ffffc90000a07da0 R14: ffffc90000a07d68 R15: ffffffff81729af5 FS: 0000000000000000(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000a6030 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3094 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3214 refdst_drop include/net/dst.h:263 [inline] skb_dst_drop include/net/dst.h:275 [inline] skb_release_head_state+0x71/0x250 net/core/skbuff.c:1136 skb_release_all net/core/skbuff.c:1150 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x60/0xf0 net/core/skbuff.c:1398 nft_synproxy_eval_v4+0x376/0x560 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141 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:157 [inline] nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:272 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6090 process_backlog+0x60e/0x14f0 net/core/dev.c:6442 __napi_poll+0xc4/0x480 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7605 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 neigh_periodic_work+0xb41/0xd60 net/core/neighbour.c:966 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245