rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20274/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=131605, q=1060 ncpus=2)
task:syz.9.3849 state:R running task stack:25400 pid:20274 tgid:20274 ppid:16905 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kasan_check_byte+0x6/0x40 mm/kasan/common.c:572
Code: f6 5b 41 5c 41 5e 41 5f e9 c7 fa ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 56 <53> 48 89 f3 49 89 fe e8 3e 15 00 00 84 c0 75 16 be 01 00 00 00 4c
RSP: 0018:ffffc90019997388 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5917473e58b2c700
RDX: 0000000000000000 RSI: ffffffff81746fa2 RDI: ffffffff8e33f2e0
RBP: ffffffff81746f85 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90019997558 R11: ffffffff81addd50 R12: 0000000000000002
R13: ffffffff8e33f2e0 R14: 0000000000000000 R15: 0000000000000000
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 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+0xbc8/0xd30 mm/page_alloc.c:2943
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x146/0x170 mm/slub.c:3886
put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961
__slab_free+0x288/0x2a0 mm/slub.c:5956
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5274
taskstats_tgid_alloc kernel/taskstats.c:576 [inline]
taskstats_exit+0x14a/0xa30 kernel/taskstats.c:615
do_exit+0x830/0x25b0 kernel/exit.c:941
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5d5abc3e89
RSP: 002b:00007ffdf800da38 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: fffffffffffffffc RBX: 00007f5d5ab462a0 RCX: 00007f5d5abc3e89
RDX: 00007f5d5ab462a0 RSI: 0000000000000058 RDI: 00007ffdf800da80
RBP: 00007f5d58db46c0 R08: 00007f5d58db46c0 R09: 00007ffdf800db67
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000006e R14: 00007ffdf800da80 R15: 00007ffdf800db68
rcu: rcu_preempt kthread starved for 403 jiffies! g131605 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:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16474 Comm: kworker/u8:26 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x44/0x3b0 kernel/locking/lockdep.c:5879
Code: 8b 05 b0 61 25 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 b3 61 25 11 83 f8 08 0f 83 87 02 00 00 89 c0 48 0f a3 05 dc f1 24 0e <73> 0d e8 f5 f8 08 00 84 c0 0f 84 a3 02 00 00 83 3d f6 21 25 0e 00
RSP: 0018:ffffc90000006d30 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff90e9e701 RCX: da2a67cc1b084a00
RDX: ffffc90000006e01 RSI: ffffffff81746f85 RDI: ffffffff8e33f2e0
RBP: dffffc0000000000 R08: ffffc90000007950 R09: 0000000000000000
R10: ffffc90000006eb8 R11: fffff52000000dd9 R12: ffffc90000007960
R13: ffffffff81746f85 R14: ffffffff8e33f2e0 R15: ffffffff81746f85
FS: 0000000000000000(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a923d10f6 CR3: 00000000612e2000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
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:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6785
nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91
nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
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:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6138 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6251
process_backlog+0x622/0x1500 net/core/dev.c:6603
__napi_poll+0xae/0x320 net/core/dev.c:7667
napi_poll net/core/dev.c:7730 [inline]
net_rx_action+0x672/0xe50 net/core/dev.c:7882
handle_softirqs+0x27d/0x850 kernel/softirq.c:626
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
wg_index_hashtable_insert+0xff/0x880 drivers/net/wireguard/peerlookup.c:126
wg_noise_handshake_create_initiation+0x574/0x750 drivers/net/wireguard/noise.c:569
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+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246