rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31629/1:b..l rcu: (detected by 0, t=10502 jiffies, g=326357, q=1581 ncpus=2) task:syz-executor state:R running task stack:22528 pid:31629 tgid:31629 ppid:31602 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7235 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:deref_stack_reg+0x1bd/0x230 arch/x86/kernel/unwind_orc.c:422 Code: 30 4c 89 c7 49 89 f7 e8 11 08 00 00 49 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 43 3a b9 00 <4c> 89 33 b0 01 eb 02 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90003b36fa0 EFLAGS: 00000246 RAX: 1ffff92000766e21 RBX: ffffc90003b37108 RCX: 0000000000000001 RDX: ffffc90003b37108 RSI: dffffc0000000000 RDI: ffffc90003b374c8 RBP: 1ffff92000766e19 R08: ffffc90003b374c8 R09: 0000000000000000 R10: ffffc90003b37118 R11: fffff52000766e25 R12: 1ffff92000766e1a R13: 1ffff92000766e1b R14: 0000000000000c40 R15: dffffc0000000000 unwind_next_frame+0x18c6/0x23c0 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5551 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4515 [inline] slab_alloc_node mm/slub.c:4844 [inline] __do_kmalloc_node mm/slub.c:5237 [inline] __kmalloc_noprof+0x316/0x760 mm/slub.c:5250 kmalloc_noprof include/linux/slab.h:954 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776 security_file_open+0xa9/0x240 security/security.c:2636 do_dentry_open+0x384/0x14e0 fs/open.c:926 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f505139babc RSP: 002b:00007ffcf45defd0 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000000049c RCX: 00007f505139babc RDX: 0000000000090800 RSI: 00007f50514325db RDI: 00000000ffffff9c RBP: 00007ffcf45df07c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000017a R13: 0000000000000000 R14: 00000000001c02bb R15: 00007ffcf45df0d0 rcu: rcu_preempt kthread starved for 531 jiffies! g326357 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1357 Comm: kworker/u8:22 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline] RIP: 0010:lock_is_held_type+0x97/0x150 kernel/locking/lockdep.c:5940 Code: eb 48 81 c3 58 0b 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 f7 01 00 00 85 c0 75 2a 49 ff c7 49 63 85 50 0b 00 00 <48> 83 c3 28 49 39 c7 7c d8 eb 11 48 c7 c7 90 e9 62 8e 4c 89 fe e8 RSP: 0018:ffffc90000a081e8 EFLAGS: 00000002 RAX: 0000000000000006 RBX: ffff88802977aa50 RCX: 0000000080000101 RDX: ffff888029779e80 RSI: ffffffff8e7602e0 RDI: ffff88802977aa50 RBP: 00000000ffffffff R08: ffff888029779e80 R09: 0000000000000002 R10: 000000000000a888 R11: 0000000000000100 R12: 0000000000000246 R13: ffff888029779e80 R14: ffffffff8e7602e0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125561000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f41a9f30000 CR3: 000000003707c000 CR4: 00000000003526f0 Call Trace: read_pnet_rcu include/net/net_namespace.h:428 [inline] dev_net_rcu include/linux/netdevice.h:2747 [inline] __netif_receive_skb_core+0x648/0x31a0 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6162 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] netif_receive_skb_internal net/core/dev.c:6363 [inline] netif_receive_skb+0x1fe/0xc50 net/core/dev.c:6422 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x14c3/0x1b70 net/bridge/br_input.c:-1 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0x80f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6051 __netif_receive_skb_one_core net/core/dev.c:6162 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6628 __napi_poll+0xae/0x340 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7912 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42 blake2s_final+0x116/0x270 lib/crypto/blake2s.c:142 hmac+0x2de/0x3b0 drivers/net/wireguard/noise.c:333 kdf+0x126/0x2b0 drivers/net/wireguard/noise.c:367 mix_dh drivers/net/wireguard/noise.c:413 [inline] wg_noise_handshake_create_initiation+0x2bc/0x830 drivers/net/wireguard/noise.c:550 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available IPVS: lblc: UDP 224.0.0.2:0 - no destination available