rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10098/1:b..l rcu: (detected by 1, t=10503 jiffies, g=35269, q=67076 ncpus=2) task:syz.8.1038 state:R running task stack:28040 pid:10098 tgid:10084 ppid:8677 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b 94 01 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900126774f0 EFLAGS: 00000206 RAX: 97f62a2b0601e800 RBX: 0000000000000000 RCX: 97f62a2b0601e800 RDX: 0000000000000000 RSI: ffffffff8db845d7 RDI: ffffffff8be28dc0 RBP: ffffffff81cf1076 R08: 0000000000000000 R09: ffffffff81cf1076 R10: dffffc0000000000 R11: ffffffff81acfe50 R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:772 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x224/0x4f0 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723 security_file_ioctl+0xcb/0x2d0 security/security.c:2913 __do_sys_ioctl fs/ioctl.c:901 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc9018e5ab RSP: 002b:00007fdc8dff6060 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdc9018e5ab RDX: 0000000000000000 RSI: 0000000000006364 RDI: 00000000000000da RBP: 00007fdc903b6160 R08: 0000000000000000 R09: 00007ffc9b0636e7 R10: 0000000000000008 R11: 0000000000000246 R12: 00007fdc903b616c R13: 0000000000000001 R14: 00007ffc9b063600 R15: 00007ffc9b0636e8 rcu: rcu_preempt kthread starved for 502 jiffies! g35269 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:25912 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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 6.16.0-rc7-syzkaller-00114-g327579671a9b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:__lock_acquire+0xabb/0xd20 kernel/locking/lockdep.c:5240 Code: 5b cd e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 6a 01 00 00 4c 89 f6 89 ea 4c 89 f9 e8 17 38 00 00 85 c0 <0f> 84 e4 01 00 00 41 f6 46 22 10 75 2e 48 8b 1c 24 4c 89 bb e0 0a RSP: 0018:ffffc90000006568 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000009 RCX: 85995d85f4420400 RDX: 0000000000000000 RSI: ffff888143ab2a58 RDI: ffff888143ab1e00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8172aae5 R10: dffffc0000000000 R11: ffffffff81acfe50 R12: 0000000064293944 R13: ffff888143ab28f0 R14: ffff888143ab2a58 R15: e834fc984f5fe27b FS: 0000000000000000(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f17581f37b0 CR3: 0000000065989000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 skb_clone+0x212/0x3a0 net/core/skbuff.c:2050 dev_queue_xmit_nit+0x416/0xcc0 net/core/dev.c:2555 xmit_one net/core/dev.c:3826 [inline] dev_hard_start_xmit+0x1be/0x830 net/core/dev.c:3846 __dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4713 dev_queue_xmit include/linux/netdevice.h:3355 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0xd03/0x1160 net/ipv4/ip_output.c:235 synproxy_send_client_synack+0x8bb/0xe20 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:272 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6090 process_backlog+0x60e/0x14f0 net/core/dev.c:6442 __napi_poll+0xc7/0x480 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7605 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:476 blake2s_compress+0x5f/0xd0 arch/x86/lib/crypto/blake2s-glue.c:46 blake2s_final+0x116/0x260 lib/crypto/blake2s.c:54 mix_hash drivers/net/wireguard/noise.c:439 [inline] message_ephemeral+0x17d/0x280 drivers/net/wireguard/noise.c:492 wg_noise_handshake_create_initiation+0x27c/0x7e0 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x163/0x320 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245