BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 148s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 148s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=8/256 refcnt=9 pending: psi_avgs_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, psi_avgs_work, psi_avgs_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=15/256 refcnt=16 in-flight: 4242:nsim_dev_trap_report_work pending: nsim_dev_trap_report_work, kfree_rcu_work, psi_avgs_work, psi_avgs_work, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, psi_avgs_work, mptcp_worker, mptcp_worker, vmstat_shepherd workqueue events_long: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: defense_work_handler pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=6/256 refcnt=7 pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, br_fdb_cleanup workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=5/512 refcnt=8 pending: cfg80211_wiphy_work, cfg80211_wiphy_work, cfg80211_wiphy_work, cfg80211_wiphy_work, flush_memcg_stats_dwork 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=2/256 refcnt=3 pending: fb_flashcursor, wg_ratelimiter_gc_entries pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4 pending: reg_check_chans_work, gc_worker, neigh_periodic_work 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 kblockd: flags=0x18 pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=1/256 refcnt=2 pending: blk_mq_timeout_work workqueue usb_hub_wq: flags=0x4 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 in-flight: 4232:hub_event hub_event pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 in-flight: 4294:hub_event hub_event workqueue ipv6_addrconf: flags=0x40008 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=2 pending: addrconf_verify_work workqueue krxrpcd: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=7 pending: rxrpc_peer_keepalive_worker inactive: rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker workqueue bat_events: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=50 in-flight: 1169:batadv_nc_worker inactive: batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_tt_purge, batadv_tt_purge, batadv_nc_worker, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_tt_purge, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_purge_orig, batadv_purge_orig, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet , batadv_iv_send_outstanding_bat_ogm_packet, batadv_iv_send_outstanding_bat_ogm_packet, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_dat_purge, batadv_bla_periodic_work, batadv_tt_purge, batadv_tt_purge, batadv_bla_periodic_work, batadv_bla_periodic_work, batadv_dat_purge, batadv_dat_purge, batadv_dat_purge, batadv_bla_periodic_work, batadv_bla_periodic_work, batadv_dat_purge workqueue wg-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=4 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 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=2/256 refcnt=5 pending: wg_packet_handshake_send_worker, wg_packet_handshake_send_worker workqueue wg-kex-wg2: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=4 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=2/256 refcnt=5 pending: wg_packet_handshake_send_worker, wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=4 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 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=4 pending: wg_packet_handshake_send_worker workqueue wg-kex-wg2: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=2/256 refcnt=5 pending: wg_packet_handshake_send_worker, wg_packet_handshake_send_worker pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=149s workers=11 idle: 13 4292 7 1107 1335 5171 4237 4225 4224 pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=149s workers=10 idle: 4247 4694 6677 4396 21 23 4264 4309 1110 pool 4: cpus=0-1 flags=0x4 nice=0 hung=149s workers=15 idle: 4331 4885 4483 4336 144 4326 4378 4399 4906 9 4223 4271 4332 154 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7790 at kernel/rcu/tree_stall.h:937 rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:929 Modules linked in: CPU: 0 PID: 7790 Comm: syz.6.808 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:rcu_check_gp_start_stall+0x2dc/0x460 kernel/rcu/tree_stall.h:937 Code: ff ff ff 48 c7 c7 20 dc 31 96 be 04 00 00 00 e8 8a df 58 00 48 89 df b8 01 00 00 00 87 05 dc 8b cc 14 85 c0 0f 85 19 ff ff ff <0f> 0b 48 81 ff 00 2f 32 8c 74 47 48 c7 c0 c4 0e 8a 8d 48 c1 e8 03 RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffff8c322f00 RCX: ffffffff81655036 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8c322f00 RBP: ffffc90000007e10 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff2c63b84 R12: 0000000000002904 R13: ffff8880b903b258 R14: 0000000000000a02 R15: dffffc0000000000 FS: 00007f0d940d16c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d7d94dfe8 CR3: 0000000060e7a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_core+0x62b/0x1670 kernel/rcu/tree.c:2758 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804 Code: be ff ff ff ff e8 6c b1 67 08 85 c0 74 4a 4d 85 ff 75 66 e9 fe 00 00 00 48 89 df e8 16 1d 71 08 e8 21 e4 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c RSP: 0018:ffffc90002f1f788 EFLAGS: 00000286 RAX: fc9ff3708b3b9300 RBX: ffff8880b903a340 RCX: fc9ff3708b3b9300 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f740 RBP: 1ffff11017207613 R08: ffff8880b903a343 R09: 1ffff11017207468 R10: dffffc0000000000 R11: ffffed1017207469 R12: ffff8880b903b088 R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x22d/0x440 kernel/futex/core.c:2863 futex_wait+0x256/0x680 kernel/futex/core.c:2964 do_futex+0xdb2/0x12b0 kernel/futex/core.c:3982 __do_sys_futex kernel/futex/core.c:4059 [inline] __se_sys_futex+0x389/0x420 kernel/futex/core.c:4040 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0d95e9cf79 Code: 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 01 48 RSP: 002b:00007f0d940d10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f0d96117098 RCX: 00007f0d95e9cf79 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0d96117098 RBP: 00007f0d96117090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0d96117128 R14: 00007ffed18ef960 R15: 00007ffed18efa48 ---------------- Code disassembly (best guess): 0: be ff ff ff ff mov $0xffffffff,%esi 5: e8 6c b1 67 08 call 0x867b176 a: 85 c0 test %eax,%eax c: 74 4a je 0x58 e: 4d 85 ff test %r15,%r15 11: 75 66 jne 0x79 13: e9 fe 00 00 00 jmp 0x116 18: 48 89 df mov %rbx,%rdi 1b: e8 16 1d 71 08 call 0x8711d36 20: e8 21 e4 2a 00 call 0x2ae446 25: fb sti 26: 48 83 c4 08 add $0x8,%rsp * 2a: 5b pop %rbx <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: 5d pop %rbp 34: c3 ret 35: 48 89 df mov %rbx,%rdi 38: e8 c9 09 fe ff call 0xfffe0a06 3d: 43 rex.XB 3e: 80 .byte 0x80 3f: 3c .byte 0x3c