rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5346/1:b..l rcu: (detected by 0, t=10503 jiffies, g=29345, q=1321430 ncpus=2) task:crond state:R running task stack:25944 pid:5346 tgid:5346 ppid:1 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_release kernel/locking/lockdep.c:5885 [inline] RIP: 0010:lock_release+0x8d/0x310 kernel/locking/lockdep.c:5875 Code: 00 00 65 4c 8b 25 fb e9 4e 12 41 8b bc 24 9c 0b 00 00 85 ff 0f 85 21 01 00 00 48 81 3b 80 c9 3a 94 0f 84 14 01 00 00 9c 41 5e 48 c7 c7 75 03 25 8e e8 26 c5 b7 09 65 ff 05 7f 30 4f 12 8b 35 RSP: 0018:ffffc9000320f4d0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff8e9e60c0 RCX: ffffffff92510101 RDX: 0000000000000000 RSI: ffffffff8c3e9a00 RDI: 0000000000000000 RBP: ffffffff81b786ae R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000a9c31 R12: ffff88801eb7a540 R13: ffffc9000320f588 R14: 0000000000000202 R15: ffffc9000320f5bc rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5362 [inline] __kmalloc_noprof+0x322/0x820 mm/slub.c:5387 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] tomoyo_encode2+0xfb/0x3c0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18c/0x690 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_statx_path fs/stat.c:299 [inline] vfs_statx+0x11f/0x3f0 fs/stat.c:356 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd4c575fb0a RSP: 002b:00007ffe725fee48 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007fd4c590f490 RCX: 00007fd4c575fb0a RDX: 00007ffe725fee68 RSI: 00007fd4c58e87e8 RDI: 00000000ffffff9c RBP: 0000000077359428 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000003c R14: 000000000cf55134 R15: 000000000000003a rcu: rcu_preempt kthread starved for 6691 jiffies! g29345 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:198 __mod_timer+0x409/0xca0 kernel/time/timer.c:1139 add_timer+0x62/0x90 kernel/time/timer.c:1249 schedule_timeout+0x122/0x280 kernel/time/sleep_timeout.c:98 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: CPU: 0 UID: 0 PID: 5811 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker RIP: 0010:lock_is_held_type+0xf5/0x140 kernel/locking/lockdep.c:5945 Code: ff ff ff ff 65 0f c1 15 19 85 97 08 83 fa 01 8b 44 24 04 75 2d 9c 5a 80 e6 02 75 47 41 f7 c5 00 02 00 00 74 01 fb 48 83 c4 08 <5b> 5d 41 5c 41 5d 41 5e 41 5f e9 7c 3f 03 00 c3 cc cc cc cc 31 c0 RSP: 0018:ffffc90000007040 EFLAGS: 00000292 RAX: 0000000000000001 RBX: ffffffff8e9e60c0 RCX: 0000000000000001 RDX: 0000000000000046 RSI: ffffffff8e137691 RDI: ffffffff8c3e9a80 RBP: ffff88802dda0000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffff R13: 0000000000000246 R14: ffff88802dda0c18 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881240e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f31533d6f4c CR3: 000000005f46f000 CR4: 00000000003526f0 Call Trace: ip_ignore_linkdown include/linux/inetdevice.h:270 [inline] fib_lookup_good_nhc+0x2f6/0x3f0 net/ipv4/fib_trie.c:1408 fib_table_lookup+0xccd/0x22d0 net/ipv4/fib_trie.c:1594 fib_lookup.constprop.0+0x13a/0x4c0 include/net/ip_fib.h:389 ip_route_output_key_hash_rcu+0xde2/0x2870 net/ipv4/route.c:2811 ip_route_output_key_hash+0x118/0x2b0 net/ipv4/route.c:2702 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2929 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x562/0x1260 net/ipv4/netfilter.c:54 synproxy_send_tcp.isra.0+0x341/0x680 net/netfilter/nf_synproxy_core.c:434 synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa1c/0xce0 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish net/ipv4/ip_input.c:492 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6206 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6319 process_backlog+0x37a/0x1580 net/core/dev.c:6670 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7949 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end arch/x86/kernel/fpu/core.c:506 [inline] kernel_fpu_end+0x64/0x80 arch/x86/kernel/fpu/core.c:499 blake2s_compress+0x78/0xf0 lib/crypto/x86/blake2s.h:42 blake2s_final+0xc9/0x160 lib/crypto/blake2s.c:142 hmac.constprop.0+0x25d/0x480 drivers/net/wireguard/noise.c:325 kdf.constprop.0+0x128/0x280 drivers/net/wireguard/noise.c:360 mix_dh+0xd2/0x130 drivers/net/wireguard/noise.c:413 wg_noise_handshake_consume_initiation+0x265/0x860 drivers/net/wireguard/noise.c:608 wg_receive_handshake_packet+0x7b2/0xc20 drivers/net/wireguard/receive.c:144 wg_packet_handshake_receive_worker+0x15e/0x370 drivers/net/wireguard/receive.c:213 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245