rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5566/1:b..l rcu: (detected by 1, t=10503 jiffies, g=119609, q=659 ncpus=2) task:crond state:R running task stack:23864 pid:5566 tgid:5566 ppid:1 task_flags:0x400000 flags:0x00080800 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7507 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x141a/0x2550 arch/x86/kernel/unwind_orc.c:670 Code: 24 41 0f b6 44 2d 00 84 c0 0f 85 fd 0e 00 00 c6 03 00 48 8b 5c 24 28 4c 8b 64 24 18 4c 8b 7c 24 38 48 8b 44 24 48 0f b6 04 28 <84> c0 0f 85 41 0c 00 00 41 0f b6 04 2f 84 c0 0f 85 5c 0c 00 00 48 RSP: 0018:ffffc90003657378 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90003657498 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff90d64002 RBP: dffffc0000000000 R08: ffffc900036574a7 R09: 0000000000000000 R10: ffffc90003657498 R11: fffff520006cae95 R12: ffffc90003657d40 R13: 1ffff920006cae8b R14: ffffc90003657448 R15: 1ffffffff21ac800 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1895 vfs_getattr+0x23/0x70 fs/stat.c:259 vfs_statx_path+0x2b/0x230 fs/stat.c:299 vfs_statx+0x12e/0x200 fs/stat.c:356 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2e98dd4b0a RSP: 002b:00007fff7e6e68b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007f2e98f84490 RCX: 00007f2e98dd4b0a RDX: 00007fff7e6e68d8 RSI: 00007f2e98f5d7e8 RDI: 00000000ffffff9c RBP: 0000000069eaec28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000003c R14: 0000000000000000 R15: 0000000000000030 rcu: rcu_preempt kthread starved for 682 jiffies! g119609 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:27528 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 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+0x514/0xb70 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5601 [inline] RIP: 0010:lock_is_held_type+0x89/0x150 kernel/locking/lockdep.c:5940 Code: 8a 07 41 83 bd 88 0b 00 00 00 7e 48 4c 89 eb 48 81 c3 90 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 88 0b 00 00 48 83 c3 28 49 39 c7 7c RSP: 0018:ffffc90000007220 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff888020690cd0 RCX: 0000000080010303 RDX: ffff888020690000 RSI: ffff8880b8628298 RDI: ffff888020690cd0 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000e40 R12: 0000000000000046 R13: ffff888020690000 R14: ffff8880b8628298 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff888125243000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003e40 CR3: 000000007e70e000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] enqueue_hrtimer+0x79/0x2c0 kernel/time/hrtimer.c:1107 __run_hrtimer kernel/time/hrtimer.c:1946 [inline] __hrtimer_run_queues+0x4d2/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235 Code: a8 16 00 00 83 fa 02 75 21 48 8b 91 b0 16 00 00 48 8b 32 48 8d 7e 01 8b 89 ac 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 8f f9 f0 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc90000007570 EFLAGS: 00000246 RAX: ffffffff897a74c6 RBX: ffff8881d1ede280 RCX: ffff888020690000 RDX: 0000000000000100 RSI: 0000000000000005 RDI: ffff8881d1ede280 RBP: 0000000000000005 R08: ffffffff90321bb7 R09: 1ffffffff2064376 R10: dffffc0000000000 R11: fffffbfff2064377 R12: ffff8881d1ede280 R13: ffff8881d1ede3c0 R14: ffff888098f60000 R15: dffffc0000000000 skb_ext_add+0x26/0x8f0 net/core/skbuff.c:7131 vxcan_xmit+0x204/0x780 drivers/net/can/vxcan.c:73 __netdev_start_xmit include/linux/netdevice.h:5371 [inline] netdev_start_xmit include/linux/netdevice.h:5380 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904 __dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870 dev_queue_xmit include/linux/netdevice.h:3421 [inline] can_send+0x921/0xd20 net/can/af_can.c:279 can_can_gw_rcv+0xcb0/0xf70 net/can/gw.c:569 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0x126/0x7a0 net/can/af_can.c:602 can_receive+0x2c6/0x440 net/can/af_can.c:674 can_rcv+0x1f9/0x330 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0xc66/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/0x840 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+0x20c/0x3b0 drivers/net/wireguard/noise.c:325 kdf drivers/net/wireguard/noise.c:360 [inline] message_ephemeral+0x233/0x310 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x257/0x830 drivers/net/wireguard/noise.c:545 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:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245