BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 159s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 159s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 156s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: kfree_rcu_monitor pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4 pending: vmstat_shepherd, psi_avgs_work, kfree_rcu_monitor workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=4/512 refcnt=6 in-flight: 45:linkwatch_event pending: fsnotify_mark_destroy_workfn, toggle_allocation_gate, flush_memcg_stats_dwork workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=5/256 refcnt=6 pending: wg_ratelimiter_gc_entries, neigh_periodic_work, neigh_periodic_work, gc_worker, check_lifetime workqueue netns: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=3 in-flight: 10: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=1/256 refcnt=3 pending: wb_workfn workqueue kblockd: flags=0x18 pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 refcnt=2 pending: blk_mq_timeout_work 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 mld: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=55 pending: mld_ifc_work inactive: mld_dad_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work, mld_dad_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=39 pending: mld_ifc_work inactive: mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_dad_work, mld_dad_work workqueue ipv6_addrconf: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=134 in-flight: 26:addrconf_dad_work inactive: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work , addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work , addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_verify_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=94 in-flight: 380:addrconf_dad_work inactive: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work , addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work 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-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=3 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-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3 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-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=3 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-kex-wg0: flags=0x6 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3 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-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=3 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 pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=161s workers=5 idle: 401 352 20 6 pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=161s workers=4 idle: 60 42 381 pool 4: cpus=0-1 flags=0x4 nice=0 hung=161s workers=5 idle: 8 384 266 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10002 jiffies, g=1681, q=458) rcu: All QSes seen, last rcu_preempt kthread activity 10003 (4294980487-4294970484), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10004 jiffies! g1681 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28688 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5178 [inline] __schedule+0xb6e/0x14c0 kernel/sched/core.c:6538 schedule+0x11e/0x1e0 kernel/sched/core.c:6621 schedule_timeout+0x159/0x340 kernel/time/timer.c:1922 rcu_gp_fqs_loop+0x2ae/0xf80 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x360 kernel/rcu/tree.c:2145 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 405 Comm: syz.2.30 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 dump_stack+0x15/0x20 lib/dump_stack.c:113 nmi_cpu_backtrace+0x2af/0x2c0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x138/0x240 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:39 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1e0/0x260 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0xe33/0x1010 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3972 [inline] rcu_sched_clock_irq+0x8b2/0x12c0 kernel/rcu/tree.c:2619 update_process_times+0x198/0x200 kernel/time/timer.c:1826 tick_sched_handle kernel/time/tick-sched.c:257 [inline] tick_sched_timer+0x17c/0x240 kernel/time/tick-sched.c:1478 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x39f/0x8c0 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x3c7/0x8c0 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0xfa/0x3e0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:202 Code: 12 48 89 fb 48 c7 c7 b8 3e 6d 86 e8 91 be f4 fc 48 89 df 48 83 3d ae 07 b9 01 00 74 27 e8 f3 bb 9b fc 66 90 fb bf 01 00 00 00 a2 90 93 fc 65 8b 05 63 36 4e 7b 85 c0 74 03 5b 5d c3 e8 c3 41 RSP: 0018:ffffc90000d17b98 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000021 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc90000d17ba0 R08: ffffc90000d17dff R09: 1ffff920001a2fbf R10: dffffc0000000000 R11: fffff520001a2fc0 R12: 1ffff11021e172b4 R13: dffffc0000000000 R14: ffff88810f0b95a0 R15: 000000001c000004 spin_unlock_irq include/linux/spinlock.h:414 [inline] get_signal+0x13b2/0x1480 kernel/signal.c:2910 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbbccb40817 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:00007fbbcc9a30e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fbbccdb9fa8 RCX: 00007fbbccb40819 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbbccdb9fa8 RBP: 00007fbbccdb9fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbbccdba038 R14: 00007fff9a516770 R15: 00007fff9a516858 ---------------- Code disassembly (best guess): 0: 12 48 89 adc -0x77(%rax),%cl 3: fb sti 4: 48 c7 c7 b8 3e 6d 86 mov $0xffffffff866d3eb8,%rdi b: e8 91 be f4 fc call 0xfcf4bea1 10: 48 89 df mov %rbx,%rdi 13: 48 83 3d ae 07 b9 01 cmpq $0x0,0x1b907ae(%rip) # 0x1b907c9 1a: 00 1b: 74 27 je 0x44 1d: e8 f3 bb 9b fc call 0xfc9bbc15 22: 66 90 xchg %ax,%ax 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 a2 90 93 fc call 0xfc9390d1 <-- trapping instruction 2f: 65 8b 05 63 36 4e 7b mov %gs:0x7b4e3663(%rip),%eax # 0x7b4e3699 36: 85 c0 test %eax,%eax 38: 74 03 je 0x3d 3a: 5b pop %rbx 3b: 5d pop %rbp 3c: c3 ret 3d: e8 .byte 0xe8 3e: c3 ret 3f: 41 rex.B