BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 171s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 171s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 168s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 pending: psi_avgs_work, kfree_rcu_monitor pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 pending: kfree_rcu_monitor, vmstat_shepherd workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=4/512 refcnt=6 in-flight: 8: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=1/256 refcnt=2 pending: neigh_periodic_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256 refcnt=5 pending: wg_ratelimiter_gc_entries, neigh_periodic_work, gc_worker, check_lifetime workqueue netns: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=4 in-flight: 45:cleanup_net inactive: 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 2: cpus=1 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=50 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_dad_work, mld_dad_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_dad_work, mld_ifc_work, mld_ifc_work, mld_dad_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_dad_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_dad_work, mld_ifc_work, mld_ifc_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=43 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_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_ifc_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_dad_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_ifc_work, mld_dad_work workqueue ipv6_addrconf: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=103 pending: 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 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=143 in-flight: 20: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_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 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=3 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-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 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-wg1: 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-wg1: flags=0x28 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: wg_packet_encrypt_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=2/256 refcnt=3 pending: wg_packet_tx_worker, 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=172s workers=5 idle: 60 421 420 6 pool 4: cpus=0-1 flags=0x4 nice=0 hung=172s workers=5 idle: 326 321 10 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10002 jiffies, g=1417, q=402) rcu: All QSes seen, last rcu_preempt kthread activity 10003 (4294980564-4294970561), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10004 jiffies! g1417 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:28752 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+0x12c/0x2e0 kernel/time/timer.c:1920 rcu_gp_fqs_loop+0x293/0xf60 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x330 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: 427 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 dump_stack+0x15/0x20 lib/dump_stack.c:113 nmi_cpu_backtrace+0x2b4/0x2c0 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+0xded/0xfd0 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+0x8a3/0x12b0 kernel/rcu/tree.c:2619 update_process_times+0x198/0x200 kernel/time/timer.c:1824 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+0x3b5/0x9e0 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:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64 Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 RSP: 0018:ffffc90000ec7c90 EFLAGS: 00010202 RAX: 00007f1efdad4b00 RBX: 0000000000000100 RCX: 0000000000000080 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffc90000ec7dc0 RBP: ffffc90000ec7cb0 R08: dffffc0000000000 R09: ffffc90000ec7d40 R10: 0000000000000000 R11: 0000000000000020 R12: ffff888112f213c0 R13: ffffc90000ec7d40 R14: 0000000000000000 R15: ffffc90000ec7d40 restore_sigcontext arch/x86/kernel/signal.c:86 [inline] __ia32_sys_rt_sigreturn+0x174/0x6c0 arch/x86/kernel/signal.c:674 x64_sys_call+0x4ab/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:16 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: 0033:0x7f1efdc01829 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f1efdad4b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f1efdebbfa8 RCX: 00007f1efdc01829 RDX: 00007f1efdad4b40 RSI: 00007f1efdad4c70 RDI: 0000000000000021 RBP: 00007f1efdebbfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f1efdebc038 R14: 00007ffe2a3061b0 R15: 00007ffe2a306298 ---------------- Code disassembly (best guess): 0: c1 e9 03 shr $0x3,%ecx 3: 40 0f b6 f6 movzbl %sil,%esi 7: 48 b8 01 01 01 01 01 movabs $0x101010101010101,%rax e: 01 01 01 11: 48 0f af c6 imul %rsi,%rax 15: f3 48 ab rep stos %rax,%es:(%rdi) 18: 89 d1 mov %edx,%ecx 1a: f3 aa rep stos %al,%es:(%rdi) 1c: 4c 89 c8 mov %r9,%rax 1f: c3 ret 20: 90 nop 21: 49 89 f9 mov %rdi,%r9 24: 40 88 f0 mov %sil,%al 27: 48 89 d1 mov %rdx,%rcx * 2a: f3 aa rep stos %al,%es:(%rdi) <-- trapping instruction 2c: 4c 89 c8 mov %r9,%rax 2f: c3 ret 30: 90 nop 31: 49 89 fa mov %rdi,%r10 34: 40 0f b6 ce movzbl %sil,%ecx 38: 48 rex.W 39: b8 01 01 01 01 mov $0x1010101,%eax 3e: 01 01 add %eax,(%rcx)