BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 140s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 208s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 202s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=13/256 refcnt=14 in-flight: 5860:switchdev_deferred_process_work switchdev_deferred_process_work pending: 2*nsim_dev_hwstats_traffic_work, 2*ovs_dp_masks_rebalance, 2*psi_avgs_work, ovs_dp_masks_rebalance, fill_page_cache_func, kfree_rcu_monitor, ima_keys_handler, rht_deferred_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=14/256 refcnt=15 pending: psi_avgs_work, free_obj_work, fill_page_cache_func, kfree_rcu_monitor, jump_label_update_timeout, 3*nsim_dev_hwstats_traffic_work, psi_avgs_work, vmstat_shepherd, 2*ovs_dp_masks_rebalance, 2*rht_deferred_worker workqueue events_long: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=9/256 refcnt=10 pending: 4*defense_work_handler, 2*br_multicast_gc_work, 3*br_fdb_cleanup pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4 in-flight: 5861:defense_work_handler pending: defense_work_handler, br_multicast_gc_work workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=6/512 refcnt=7 in-flight: 2874:linkwatch_event linkwatch_event pending: nsim_dev_trap_report_work, 3*macvlan_process_broadcast, idle_cull_fn pwq 4: cpus=0-1 flags=0x4 nice=0 active=19/512 refcnt=20 in-flight: 12:cfg80211_wiphy_work pending: 4*nsim_dev_trap_report_work, toggle_allocation_gate, flush_memcg_stats_dwork, 6*cfg80211_wiphy_work, 3*macvlan_process_broadcast, crng_reseed, idle_cull_fn workqueue events_freezable: flags=0x4 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: update_balloon_stats_func workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=6/256 refcnt=7 pending: wg_ratelimiter_gc_entries, neigh_managed_work, do_cache_clean, neigh_periodic_work, gc_worker, check_lifetime pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 pending: neigh_managed_work, neigh_periodic_work workqueue netns: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=4 in-flight: 4696:cleanup_net workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_update pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_update workqueue writeback: flags=0x4a pwq 4: cpus=0-1 flags=0x4 nice=0 active=2/256 refcnt=3 pending: 2*wb_workfn workqueue kblockd: flags=0x18 pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=2/256 refcnt=3 pending: 2*blk_mq_timeout_work workqueue gid-cache-wq: flags=0xa0002 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=8 pending: update_gid_event_work_handler inactive: 4*update_gid_event_work_handler workqueue dm_bufio_cache: flags=0x8 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: work_fn workqueue ipv6_addrconf: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=9 in-flight: 2876:addrconf_verify_work inactive: 5*addrconf_verify_work workqueue krxrpcd: flags=0xa001a pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=8 pending: rxrpc_peer_keepalive_worker inactive: 4*rxrpc_peer_keepalive_worker workqueue bat_events: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=44 pending: batadv_nc_worker inactive: 3*batadv_nc_worker, 5*batadv_mcast_mla_update, batadv_iv_send_outstanding_bat_ogm_packet, 5*batadv_purge_orig, 10*batadv_iv_send_outstanding_bat_ogm_packet, batadv_nc_worker, batadv_tt_purge, batadv_dat_purge, batadv_bla_periodic_work, 4*batadv_tt_purge, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work workqueue wg-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue hci0: flags=0xa0012 pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=4 pending: hci_conn_timeout workqueue wg-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue hci2: flags=0xa0012 pwq 5: cpus=0-1 node=0 flags=0x4 nice=-20 active=1/1 refcnt=4 pending: hci_conn_timeout pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=141s workers=8 idle: 5610 9 8 1188 5812 5825 5840 pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=209s workers=7 idle: 5895 788 23 27 6535 5773 pool 4: cpus=0-1 flags=0x4 nice=0 hung=208s workers=12 idle: 11 59 7187 42 77 49 62 5984 Showing backtraces of running workers in stalled CPU-bound worker pools: pool 0: task:kworker/0:7 state:R running task stack:24680 pid:5861 ppid:2 flags:0x00004000 Workqueue: events_long defense_work_handler Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] nr_blockdev_pages+0xea/0x100 block/bdev.c:461 si_meminfo+0x10f/0x180 mm/show_mem.c:83 update_defense_level+0xc7/0xe10 net/netfilter/ipvs/ip_vs_ctl.c:101 defense_work_handler+0x2d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7191 at kernel/rcu/tree_stall.h:1001 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:993 Modules linked in: CPU: 0 PID: 7191 Comm: syz.4.294 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:1001 Code: ff ff ff 48 c7 c7 a0 d4 2e 97 be 04 00 00 00 e8 fa c7 6d 00 48 89 df b8 01 00 00 00 87 05 3c 80 bd 15 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 40 52 13 8d 74 47 48 c7 c0 ec 93 8a 8e 48 c1 e8 03 RSP: 0018:ffffc90000007c58 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffff8d135240 RCX: ffffffff81715456 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8d135240 RBP: ffffc90000007ed0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff2e5da94 R12: 0000000000002904 R13: ffffffff8d135240 R14: 0000000000000a06 R15: dffffc0000000000 FS: 00007f1d3ae796c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000bbdffc CR3: 00000000613ea000 CR4: 00000000003506f0 Call Trace: rcu_core+0x635/0x1770 kernel/rcu/tree.c:2462 handle_softirqs+0x280/0x820 kernel/softirq.c:578 do_softirq+0xfa/0x1a0 kernel/softirq.c:479 __local_bh_enable_ip+0x184/0x1c0 kernel/softirq.c:406 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline] copy_fpstate_to_sigframe+0x4b3/0xc60 arch/x86/kernel/fpu/signal.c:233 get_sigframe+0x5e2/0x7d0 arch/x86/kernel/signal.c:142 x64_setup_rt_frame+0x15e/0xc40 arch/x86/kernel/signal_64.c:175 setup_rt_frame arch/x86/kernel/signal.c:223 [inline] handle_signal arch/x86/kernel/signal.c:267 [inline] arch_do_signal_or_restart+0x42c/0x800 arch/x86/kernel/signal.c:312 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1d39f9acb7 Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 RSP: 002b:00007f1d3ae790e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f1d3a216098 RCX: 00007f1d39f9acb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1d3a216098 RBP: 00007f1d3a216090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d3a216128 R14: 00007ffc16e85f80 R15: 00007ffc16e86068