rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25105/1:b..l rcu: (detected by 0, t=10503 jiffies, g=107549, q=1335964 ncpus=2) task:syz.3.5429 state:R running task stack:22152 pid:25105 tgid:25105 ppid:21300 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893 Code: 75 52 11 00 00 00 00 eb b5 e8 c5 8e f6 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 b5 2f 52 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 85 c0 6f ff cc 48 8d 3d 52 e7 51 RSP: 0018:ffffc9000e737038 EFLAGS: 00000282 RAX: 6e0af7227c170900 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8df34b56 RDI: ffffffff8c073a00 RBP: ffff88803499c830 R08: ffff88801e89c5e7 R09: 1ffff11003d138bc R10: dffffc0000000000 R11: ffffed1003d138bd R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e55a360 R15: ffff88803499bd00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] __update_page_owner_free_handle+0x451/0x470 mm/page_owner.c:295 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xdce/0x1510 mm/page_alloc.c:3030 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:837 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x691/0xa70 fs/file_table.c:476 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x69b/0x2310 kernel/exit.c:971 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x176/0x620 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f51c819aec1 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f51c8416090 RCX: 00007f51c819aeb9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f51c8208c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f51c8416128 R14: 00007f51c8416090 R15: 00007fff8dd23a38 rcu: rcu_preempt kthread starved for 558 jiffies! g107549 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:28000 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 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: 16616 Comm: kworker/u8:12 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:dst_init+0x14c/0x480 net/core/dst.c:60 Code: 28 ba 10 00 00 00 31 f6 e8 91 3d bf f8 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 9c 3b bf f8 49 c7 46 28 b0 8f 6d 89 <49> 8d 7e 30 48 89 f8 48 c1 e8 03 80 3c 28 00 74 05 e8 7e 3b bf f8 RSP: 0018:ffffc90000006e50 EFLAGS: 00000246 RAX: 1ffff11033d61245 RBX: ffff88819eb09228 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff88819eb09228 RBP: dffffc0000000000 R08: ffff88819eb09227 R09: ffff88819eb09218 R10: dffffc0000000000 R11: ffffed1033d61245 R12: ffff8880a4578618 R13: 0000000000000002 R14: ffff88819eb09200 R15: ffffffff8fa7b080 FS: 0000000000000000(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d8cfe2698 CR3: 00000000314cf000 CR4: 0000000000350ef0 Call Trace: dst_alloc+0x12a/0x170 net/core/dst.c:94 rt_dst_alloc net/ipv4/route.c:1651 [inline] __mkroute_output net/ipv4/route.c:2655 [inline] ip_route_output_key_hash_rcu+0x14d0/0x25d0 net/ipv4/route.c:2875 ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2705 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2932 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x742/0xf90 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x34c/0x670 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8c1/0xe30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x45e/0x1990 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x29d/0x380 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6152 [inline] __netif_receive_skb net/core/dev.c:6265 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6617 __napi_poll+0xae/0x340 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7896 handle_softirqs+0x22a/0x7c0 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+0xff/0x2b0 drivers/net/wireguard/noise.c:360 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:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246