INFO: task kworker/u8:9:2970 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:9 state:D stack:21192 pid:2970 tgid:2970 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 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+0x7e6/0x1350 kernel/locking/mutex.c:760 wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:417 ops_pre_exit_list net/core/net_namespace.c:160 [inline] ops_undo_list+0x184/0x990 net/core/net_namespace.c:233 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 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 kthreadd/2: 4 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/36: 1 lock held by khugepaged/38: #0: ffffffff8e1fe428 (lock#3){+.+.}-{4:4}, at: __lru_add_drain_all+0x66/0x5e0 mm/swap.c:835 9 locks held by kworker/1:1/43: 4 locks held by kworker/u8:3/49: #0: ffff88804dab9148 ((wq_completion)wg-kex-wg1#11){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88804dab9148 ((wq_completion)wg-kex-wg1#11){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000b97bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000b97bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff888022345308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x10a/0x7e0 drivers/net/wireguard/noise.c:529 #3: ffff88807a0ebea8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x11b/0x7e0 drivers/net/wireguard/noise.c:530 4 locks held by kworker/u8:4/59: 2 locks held by kswapd0/86: 3 locks held by kworker/u8:6/1096: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900038d7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900038d7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:7/1113: 3 locks held by kworker/1:2/1932: 4 locks held by kworker/u8:9/2970: #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000b02fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000b02fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f52c3d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:417 4 locks held by kworker/u8:10/2999: 3 locks held by kworker/R-ipv6_/3205: #0: ffff88802f7e8148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88802f7e8148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000b3bfba0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000b3bfba0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 5 locks held by kworker/R-bat_e/3429: 1 lock held by dhcpcd/5531: 1 lock held by crond/5609: 2 locks held by getty/5627: #0: ffff8880338b90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5853: 5 locks held by kworker/1:3/5936: 4 locks held by kworker/1:4/5937: 3 locks held by kworker/1:6/5983: #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000aab7bc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000aab7bc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf30 net/wireless/reg.c:2483 5 locks held by kworker/1:7/6010: 3 locks held by kworker/1:0/9692: 2 locks held by kworker/1:5/9693: 3 locks held by kworker/0:5/9699: 4 locks held by kworker/0:9/9700: 2 locks held by kworker/1:9/9710: 3 locks held by syz.4.1389/11648: 3 locks held by syz.1.1406/11720: 1 lock held by syz.3.1409/11729: #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.4.1408/11731: #0: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f539288 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3433 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.4.1408/11735: 4 locks held by kworker/u8:0/11739: 2 locks held by kworker/u8:5/11740: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000452fbc0 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000452fbc0 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 ============================================= 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_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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/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: 3429 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_dat_purge RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5844 Code: f6 05 49 1e f0 0d 01 0f 84 d7 01 00 00 83 3d b9 69 06 0e 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 c3 97 85 00 <83> 3d 9c 69 06 0e 00 0f 84 fa 00 00 00 65 8b 05 5f 62 03 11 85 c0 RSP: 0000:ffffc90000a07c98 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 71814890a592b300 RDX: 0000000000000000 RSI: ffffffff8172c1b2 RDI: 1ffffffff1c273e4 RBP: ffffffff8172c195 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000a07e58 R11: ffffffff81ac3ae0 R12: 0000000000000002 R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000003cb030 CR3: 000000007a30c000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4797 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1397 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: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 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:5991 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6104 process_backlog+0x60e/0x14f0 net/core/dev.c:6456 __napi_poll+0xc7/0x360 net/core/dev.c:7506 napi_poll net/core/dev.c:7569 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7696 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge net/batman-adv/distributed-arp-table.c:185 [inline] batadv_dat_purge+0x2da/0x3c0 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3496 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245