rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10249/1:b..l rcu: (detected by 0, t=10502 jiffies, g=43281, q=825 ncpus=2) task:sed state:R running task stack:23712 pid:10249 tgid:10249 ppid:10247 task_flags:0x40000c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg+0x33/0x230 arch/x86/kernel/unwind_orc.c:419 Code: 53 48 83 ec 20 48 89 54 24 18 49 89 f0 49 89 ff 48 be 00 00 00 00 00 fc ff df 48 8d 5f 08 49 89 dc 49 c1 ec 03 41 80 3c 34 00 <4c> 89 04 24 74 16 48 89 df e8 3f dd ad 00 4c 8b 04 24 48 be 00 00 RSP: 0018:ffffc9000c94f560 EFLAGS: 00000246 RAX: fffffffffffffff0 RBX: ffffc9000c94f690 RCX: 0000000000000000 RDX: ffffc9000c94f6c8 RSI: dffffc0000000000 RDI: ffffc9000c94f688 RBP: dffffc0000000000 R08: ffffc9000c94fe78 R09: 0000000000000000 R10: ffffc9000c94f6d8 R11: fffff52001929edd R12: 1ffff92001929ed2 R13: 1ffff92001929ed3 R14: ffffc9000c94f688 R15: ffffc9000c94f688 unwind_next_frame+0x18cc/0x23d0 arch/x86/kernel/unwind_orc.c:-1 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:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x1fb/0x6d0 mm/slub.c:5776 kmalloc_noprof include/linux/slab.h:957 [inline] slab_free_hook mm/slub.c:2492 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x163/0x8d0 mm/slub.c:6781 exit_mmap+0x52c/0xb10 mm/mmap.c:1302 __mmput+0xcb/0x3d0 kernel/fork.c:1173 exit_mm+0x169/0x230 kernel/exit.c:581 do_exit+0x627/0x22f0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f134f39c6c5 RSP: 002b:00007ffd81c2de48 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f134f49dfe8 RCX: 00007f134f39c6c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f134f49c680 R15: 00007f134f49e000 rcu: rcu_preempt kthread starved for 10363 jiffies! g43281 f0x0 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:27544 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: c3 c2 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 c7 16 00 f3 0f 1e fa fb f4 98 c2 03 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8d207dc0 EFLAGS: 000002c6 RAX: 00000000009683db RBX: ffffffff8195d75e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8ce0bbf9 RDI: ffffffff8b3f57e0 RBP: ffffffff8d207eb0 R08: ffff8880b8833c5b R09: 1ffff1101710678b R10: dffffc0000000000 R11: ffffed101710678c R12: ffffffff8edb3470 R13: 1ffffffff1a60668 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c35ecf9 CR3: 0000000042018000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x381/0x3d0 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 140s! Showing busy workqueues and worker pools: workqueue events: flags=0x100 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=16 refcnt=17 pending: rht_deferred_worker, 6*nsim_dev_hwstats_traffic_work, 3*psi_avgs_work, 3*ovs_dp_masks_rebalance, 2*rht_deferred_worker, vmstat_shepherd pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=15 refcnt=16 pending: 4*nsim_dev_hwstats_traffic_work, 2*psi_avgs_work, 3*ovs_dp_masks_rebalance, psi_avgs_work, l2cap_chan_timeout, switchdev_deferred_process_work, 3*rht_deferred_worker workqueue events_highpri: flags=0x110 pwq 7: cpus=1 node=0 flags=0x0 nice=-20 active=2 refcnt=3 in-flight: 59:snd_vmidi_output_work snd_vmidi_output_work workqueue events_long: flags=0x100 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=6 refcnt=7 pending: 4*defense_work_handler, br_multicast_gc_work, br_fdb_cleanup pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=8 refcnt=9 pending: 2*defense_work_handler, 2*br_multicast_gc_work, br_fdb_cleanup, 2*br_multicast_gc_work, br_fdb_cleanup workqueue events_unbound: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 pending: toggle_allocation_gate, flush_memcg_stats_dwork workqueue events_unbound: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=22 refcnt=23 in-flight: 2448:nsim_dev_trap_report_work ,1533:nsim_dev_trap_report_work ,9381:nsim_dev_trap_report_work ,4248:nsim_dev_trap_report_work ,89:cfg80211_wiphy_work ,7356:nsim_dev_trap_report_work ,1468:cfg80211_wiphy_work pending: 5*nsim_dev_trap_report_work, 10*cfg80211_wiphy_work pwq 8: cpus=0-1 flags=0x4 nice=0 active=7 refcnt=8 pending: 4*macvlan_process_broadcast, crng_reseed, 2*macvlan_process_broadcast workqueue events_freezable: flags=0x104 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: update_balloon_stats_func workqueue events_power_efficient: flags=0x180 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_ratelimiter_gc_entries, check_lifetime pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=8 refcnt=9 pending: gc_worker, 2*neigh_managed_work, neigh_periodic_work, do_cache_clean, neigh_periodic_work, 2*check_lifetime workqueue events_bh_highpri: flags=0x111 pwq 1: cpus=0 node=0 flags=0x5 bh-hi active=1 refcnt=2 in-flight: bh-hi:usb_giveback_urb_bh workqueue kvfree_rcu_reclaim: flags=0xa pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: kfree_rcu_monitor pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: kfree_rcu_monitor workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: vmstat_update pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: vmstat_update workqueue pm: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 in-flight: 6008:pm_runtime_work workqueue writeback: flags=0x4a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wb_workfn workqueue usb_hub_wq: flags=0x104 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 in-flight: 6542:hub_event workqueue iou_exit: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: io_ring_exit_work workqueue ipv6_addrconf: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=5 pending: addrconf_verify_work inactive: addrconf_verify_work workqueue krxrpcd: flags=0x2001a pwq 9: cpus=0-1 node=0 flags=0x4 nice=-20 active=1 refcnt=9 pending: rxrpc_peer_keepalive_worker inactive: 5*rxrpc_peer_keepalive_worker workqueue krdsd: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=4 pending: rds_send_worker workqueue bat_events: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=43 pending: batadv_iv_send_outstanding_bat_ogm_packet inactive: 9*batadv_iv_send_outstanding_bat_ogm_packet, 5*batadv_mcast_mla_update, 2*batadv_iv_send_outstanding_bat_ogm_packet, 4*batadv_purge_orig, batadv_iv_send_outstanding_bat_ogm_packet, batadv_purge_orig, batadv_tt_purge, 2*batadv_iv_send_outstanding_bat_ogm_packet, 4*batadv_tt_purge, batadv_bla_periodic_work, batadv_dat_purge, 2*batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, 2*batadv_dat_purge workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 pending: 2*wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 pending: 2*wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue hci3: flags=0x20012 pwq 9: cpus=0-1 node=0 flags=0x4 nice=-20 active=1 refcnt=4 pending: hci_conn_timeout workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x128 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 pending: 2*wg_packet_handshake_send_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x128 pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pool 1: cpus=0 node=0 flags=0x5 bh-hi hung=0s workers=1 pool 2: cpus=0 node=0 flags=0x0 nice=0 hung=140s workers=17 idle: 5800 9417 8857 6599 5990 10 920 6012 6790 9 992 5999 6738 5886 5948 6011 pool 7: cpus=1 node=0 flags=0x0 nice=-20 hung=0s workers=3 idle: 32 8345 pool 8: cpus=0-1 flags=0x4 nice=0 hung=84s workers=26 idle: 4274 9512 6239 6051 6882 1008 68 13 977 58 43 3490 1141 3524 9301 1127 12 1111 Showing backtraces of running workers in stalled CPU-bound worker pools: