rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9578/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=43693, q=914660 ncpus=2)
task:syz.3.989 state:R running task stack:24104 pid:9578 tgid:9578 ppid:5875 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:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 eb e3 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000b9d6ab8 EFLAGS: 00000206
RAX: 5211e0112d9b0800 RBX: 0000000000000000 RCX: 5211e0112d9b0800
RDX: 0000000000000000 RSI: ffffffff8dba5fdf RDI: ffffffff8be33400
RBP: ffffffff8172c195 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc9000b9d6c78 R11: ffffffff81ac3890 R12: 0000000000000002
R13: ffffffff8e139ee0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
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
zap_pte_range mm/memory.c:1765 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x3b31/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x420 kernel/fork.c:1130
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
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:225 [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: 0033:0x7f43fb58ebe9
RSP: 002b:00007f43fb8dfb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f43fb7b7da0 RCX: 00007f43fb58ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f43fb7b7da0 R08: 0000000000000140 R09: 00000012fb8dfe7f
R10: 00007f43fb7b7cb0 R11: 0000000000000246 R12: 000000000005e1df
R13: 00007f43fb7b6270 R14: ffffffffffffffff R15: 00007f43fb8dfca0
rcu: rcu_preempt kthread starved for 1203 jiffies! g43693 f0x2 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:27432 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:463
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: 1167 Comm: kworker/u8:7 Not tainted 6.17.0-rc1-syzkaller-00016-g8742b2d8935f #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:deref_stack_reg+0x1cb/0x230 arch/x86/kernel/unwind_orc.c:408
Code: c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 13 31 b0 00 4c 89 33 b0 01 eb 02 31 c0 48 83 c4 20 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 07 33 09 0a cc 44 89 f9 80 e1 07 80
RSP: 0018:ffffc90000a07c28 EFLAGS: 00000282
RAX: 1ffff92000140f01 RBX: ffffffff90349cb2 RCX: 0000000000000001
RDX: ffffc90000a07d68 RSI: dffffc0000000000 RDI: ffffc90003e5fc70
RBP: 1ffff92000140fa5 R08: ffffc90003e5fc70 R09: 0000000000000000
R10: ffffc90000a07d78 R11: fffff52000140fb1 R12: 1ffff92000140fa6
R13: 1ffff92000140fa7 R14: ffff88801a4a005c R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000c5030 CR3: 0000000025d08000 CR4: 00000000003526f0
Call Trace:
unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
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:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4281
__alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
synproxy_send_client_synack+0x16c/0xe20 net/netfilter/nf_synproxy_core.c:460
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:7489
napi_poll net/core/dev.c:7552 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7679
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_update+0x14b/0x450 lib/crypto/blake2s.c:33
hmac+0x1b6/0x330 drivers/net/wireguard/noise.c:324
kdf drivers/net/wireguard/noise.c:367 [inline]
message_ephemeral+0x1e2/0x280 drivers/net/wireguard/noise.c:493
wg_noise_handshake_create_initiation+0x27c/0x7e0 drivers/net/wireguard/noise.c:545
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 kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245