rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5620/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=74633, q=1150 ncpus=2)
task:syz-executor state:R running task stack:21568 pid:5620 tgid:5620 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
RIP: 0010:unwind_next_frame+0xcb2/0x2550 arch/x86/kernel/unwind_orc.c:614
Code: 39 d8 0f 97 c1 4c 39 f8 0f 96 c0 20 c8 3c 01 0f 85 76 0e 00 00 48 89 d7 e8 eb 23 00 00 48 89 c3 49 bc 00 00 00 00 00 fc ff df <48> 8b 44 24 20 42 80 3c 20 00 4d 8d 7e 48 74 08 4c 89 ff e8 06 06
RSP: 0018:ffffc90002f1f448 EFLAGS: 00000202
RAX: ffffffff81b1f9a9 RBX: ffffffff81b1f9a9 RCX: 1ffff920005e3e01
RDX: ffffc90002f1f5d8 RSI: 0000000000000002 RDI: ffffc90002f1f5d8
RBP: 1ffffffff21db776 R08: ffffc90002f1f5e0 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffc90002f20000 R14: ffffc90002f1f548 R15: ffffc90002f18000
__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: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+0xc1e/0xd10 mm/page_alloc.c:2950
__slab_free+0x274/0x2c0 mm/slub.c:5741
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 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:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931
alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262
path_openat+0x8f/0x3830 fs/namei.c:4849
do_file_open+0x23e/0x4a0 fs/namei.c:4892
do_sys_openat2+0x115/0x200 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff8a819d1bc
RSP: 002b:00007ffdf4a411b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff8a823330a RCX: 00007ff8a819d1bc
RDX: 0000000000090800 RSI: 00007ffdf4a42360 RDI: 00000000ffffff9c
RBP: 00007ffdf4a4234c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffdf4a42360
R13: 00007ff8a823330a R14: 000000000009d99c R15: 00007ffdf4a423a0
rcu: rcu_preempt kthread starved for 326 jiffies! g74633 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
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: 8034 Comm: kworker/u8:13 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:ipv6_masked_addr_cmp include/net/ipv6.h:519 [inline]
RIP: 0010:ip6_packet_match net/ipv6/netfilter/ip6_tables.c:61 [inline]
RIP: 0010:ip6t_do_table+0x5ac/0x15b0 net/ipv6/netfilter/ip6_tables.c:306
Code: 8b 37 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ef e8 cd 87 a1 f7 4d 8d 7c 24 30 4d 33 75 00 <4c> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 80 3c 28 00
RSP: 0018:ffffc90000006c60 EFLAGS: 00000246
RAX: 1ffff1100c2a1272 RBX: ffff88817888cb00 RCX: dffffc0000000000
RDX: ffff88801e3f5d00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000006e50 R08: ffffc90000006dcf R09: ffffc90000006db0
R10: dffffc0000000000 R11: fffff52000000dba R12: ffff888061509380
R13: ffff888061509390 R14: 0000000000000000 R15: ffff8880615093b0
FS: 0000000000000000(0000) GS:ffff888124f50000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555938dca38 CR3: 0000000035448000 CR4: 0000000000350ef0
Call Trace:
ip6table_mangle_hook+0x2b8/0x730 net/ipv6/netfilter/ip6table_mangle.c:73
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook+0x22a/0x3a0 include/linux/netfilter.h:273
NF_HOOK_COND include/linux/netfilter.h:306 [inline]
ip6_output+0x302/0x540 net/ipv6/ip6_output.c:246
synproxy_send_tcp_ipv6+0x549/0x700 net/netfilter/nf_synproxy_core.c:861
synproxy_send_client_synack_ipv6+0x83f/0xcd0 net/netfilter/nf_synproxy_core.c:907
nft_synproxy_eval_v6+0x362/0x4e0 net/netfilter/nft_synproxy.c:90
nft_synproxy_do_eval+0x3d1/0x550 net/netfilter/nft_synproxy.c:145
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_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6212 [inline]
__netif_receive_skb net/core/dev.c:6325 [inline]
process_backlog+0x774/0x1860 net/core/dev.c:6676
__napi_poll+0xaa/0x330 net/core/dev.c:7735
napi_poll net/core/dev.c:7798 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7955
handle_softirqs+0x225/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
blake2s_compress+0xfa/0x1c00 lib/crypto/x86/blake2s.h:42
blake2s_update+0x140/0x450 lib/crypto/blake2s.c:119
hmac+0x1f4/0x3b0 drivers/net/wireguard/noise.c:324
kdf+0x12d/0x290 drivers/net/wireguard/noise.c:367
mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline]
wg_noise_handshake_create_initiation+0x460/0x810 drivers/net/wireguard/noise.c:560
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:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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