rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10047/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=54333, q=582363 ncpus=2)
task:syz.4.751 state:R running task stack:25576 pid:10047 tgid:10043 ppid:8441 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x1300/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c
RSP: 0018:ffffc9000b69ef78 EFLAGS: 00000a03
RAX: 1ffffffff1f7da67 RBX: ffffffff8fbed33c RCX: 0000000000000000
RDX: ffffffff8fbed33c RSI: ffffffff903efd48 RDI: ffffffff8be2fda0
RBP: ffffffff8fbed33c R08: 0000000000000001 R09: ffffffff8172bd05
R10: ffffc9000b69f098 R11: ffffffff81ac1ea0 R12: ffffffff822c1a50
R13: ffffffff8fbed33c R14: ffffc9000b69f048 R15: ffffffff8fbed33c
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: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:1395 [inline]
free_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952
folios_put_refs+0x559/0x640 mm/swap.c:997
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x44c/0xb50 mm/mmap.c:1293
__mmput+0x118/0x430 kernel/fork.c:1125
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:952
do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:224 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa6d358eb69
RSP: 002b:00007fa6d13b4038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000001000 RBX: 00007fa6d37b6160 RCX: 00007fa6d358eb69
RDX: 0000000000000000 RSI: 00000000000847ba RDI: 0000000000000005
RBP: 00007fa6d3611df1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa6d37b6160 R15: 00007fa6d38dfa28
rcu: rcu_preempt kthread starved for 203 jiffies! g54333 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5970 Comm: kworker/1:6 Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x2f/0x90 kernel/kcov.c:314
Code: 8b 04 24 65 48 8b 14 25 08 40 9c 92 65 8b 0d 38 b8 dc 10 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 3c 16 00 00 00 <74> 52 8b 8a 18 16 00 00 83 f9 03 75 47 48 8b 8a 20 16 00 00 44 8b
RSP: 0018:ffffc90000a07bf8 EFLAGS: 00000246
RAX: ffffffff895bd05f RBX: 0000000008000000 RCX: 0000000000000100
RDX: ffff88803039bc00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a07cf0 R08: ffffffff8fa1b837 R09: 1ffffffff1f43706
R10: dffffc0000000000 R11: fffffbfff1f43707 R12: ffff888056a6a000
R13: dffffc0000000000 R14: ffff88819a013a00 R15: ffff88807925e000
FS: 0000000000000000(0000) GS:ffff888125d5c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557658f5c8 CR3: 0000000063b16000 CR4: 00000000003526f0
Call Trace:
skb_frags_readable include/linux/skbuff.h:1845 [inline]
validate_xmit_unreadable_skb net/core/dev.c:3904 [inline]
validate_xmit_skb+0xcf/0x11b0 net/core/dev.c:3931
__dev_queue_xmit+0x1612/0x3b50 net/core/dev.c:4705
dev_queue_xmit include/linux/netdevice.h:3358 [inline]
neigh_hh_output include/net/neighbour.h:531 [inline]
neigh_output include/net/neighbour.h:545 [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:158 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:5979 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6092
process_backlog+0x60e/0x14f0 net/core/dev.c:6444
__napi_poll+0xc7/0x360 net/core/dev.c:7497
napi_poll net/core/dev.c:7560 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7687
handle_softirqs+0x283/0x870 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:479
blake2s_compress+0x5f/0xd0 lib/crypto/x86/blake2s-glue.c:46
blake2s_final+0x116/0x260 lib/crypto/blake2s.c:55
hmac+0x293/0x330 drivers/net/wireguard/noise.c:333
kdf+0xde/0x270 drivers/net/wireguard/noise.c:360
mix_psk drivers/net/wireguard/noise.c:448 [inline]
wg_noise_handshake_create_response+0x50a/0x970 drivers/net/wireguard/noise.c:707
wg_packet_send_handshake_response+0xf6/0x2d0 drivers/net/wireguard/send.c:94
wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline]
wg_packet_handshake_receive_worker+0x627/0xfb0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245