rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5631/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=31057, q=1146011 ncpus=2)
task:syz-executor    state:R  running task     stack:22208 pid:5631  tgid:5631  ppid:1      task_flags:0x40054c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7606
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x32/0xe0 kernel/rcu/tree_plugin.h:435
Code: 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d d9 40 e8 11 48 8d 9f c4 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c <84> c0 75 4f ff 0b 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03
RSP: 0018:ffffc9000436f478 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffff88807f4084c4 RCX: 0000000000000046
RDX: ffffc9000436f501 RSI: ffffffff8e69f0c4 RDI: ffff88807f408000
RBP: 1ffffffff2222801 R08: ffffc9000436f630 R09: 0000000000000000
R10: ffffc9000436f5f8 R11: fffff5200086dec1 R12: 1ffff1100fe81098
R13: ffffffff8177f1df R14: ffffc9000436f5a8 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:882 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0x1baf/0x2550 arch/x86/kernel/unwind_orc.c:709
 __unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x122/0x230 mm/page_owner.c:183
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 free_pages_prepare+0x9eb/0xaf0 mm/page_alloc.c:1463
 __free_contig_range_common+0x174/0x340 mm/page_alloc.c:7072
 __free_contig_range mm/page_alloc.c:7117 [inline]
 free_pages_bulk+0x48/0x120 mm/page_alloc.c:5322
 vm_area_free_pages mm/vmalloc.c:3461 [inline]
 vfree+0x231/0x490 mm/vmalloc.c:3510
 kcov_put kernel/kcov.c:451 [inline]
 kcov_close+0x28/0x50 kernel/kcov.c:556
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1012
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1155
 get_signal+0x121b/0x12c0 kernel/signal.c:3112
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb11075e98e
RSP: 002b:00007fb110b4fd28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000555579ee9500 RCX: 00007fb11075e98e
RDX: 00007fb110b4fd80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb110b4fdec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000057
R13: 0000000000000038 R14: 0000000000029807 R15: 00007fb110b4fe40
 </TASK>
rcu: rcu_preempt kthread starved for 414 jiffies! g31057 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
 kthread+0x38b/0x480 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
 </TASK>
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: 420 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63
Code: f5 48 8b 74 24 20 48 c7 c7 00 ad 6d 8c e8 58 2c 41 f5 e8 f3 2a 4c f5 eb ae 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 89 fe 48 c7 c7 80 ac 6d 8c e9 0d ff ff ff cc cc cc
RSP: 0018:ffffc90000a17d80 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000071bee9f RSI: 00000000db147cf1 RDI: ffffffff8e69f0c4
RBP: ffff8880227dddc0 R08: ffffffff8177f1df R09: 0000000000000000
R10: ffffc90000a17f18 R11: ffffffff81b293f0 R12: ffffffff8ed5c920
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff888124dca000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001ff030 CR3: 000000004b234000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
 lock_acquire+0x125/0x350 kernel/locking/lockdep.c:5945
 rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
 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
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_node_noprof+0x354/0x610 mm/slub.c:5068
 __alloc_skb+0x1db/0x7a0 net/core/skbuff.c:704
 alloc_skb include/linux/skbuff.h:1384 [inline]
 synproxy_send_client_synack+0x175/0xde0 net/netfilter/nf_synproxy_core.c:463
 nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
 nft_synproxy_do_eval+0x389/0x5d0 net/netfilter/nft_synproxy.c:142
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
 nft_do_chain_ipv4+0x195/0x290 net/netfilter/nft_chain_filter.c:24
 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:280 [inline]
 NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
 __netif_receive_skb_one_core net/core/dev.c:6265 [inline]
 __netif_receive_skb net/core/dev.c:6378 [inline]
 process_backlog+0xa6b/0x18b0 net/core/dev.c:6729
 __napi_poll+0xaa/0x330 net/core/dev.c:7798
 napi_poll net/core/dev.c:7861 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:8018
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 do_softirq+0x77/0xd0 kernel/softirq.c:546
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
 blake2s_compress+0xfa/0x1c00 lib/crypto/x86/blake2s.h:42
 blake2s_final+0x10f/0x270 lib/crypto/blake2s.c:142
 hmac+0x2dc/0x3b0 drivers/net/wireguard/noise.c:333
 kdf drivers/net/wireguard/noise.c:367 [inline]
 message_ephemeral+0x255/0x310 drivers/net/wireguard/noise.c:493
 wg_noise_handshake_create_initiation+0x24f/0x810 drivers/net/wireguard/noise.c:545
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline]
 wg_packet_handshake_send_worker+0x18c/0x370 drivers/net/wireguard/send.c:51
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 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
 </TASK>