rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10621/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=45261, q=837051 ncpus=2)
task:syz.5.1030 state:R running task stack:24888 pid:10621 tgid:10619 ppid:8325 task_flags:0x400040 flags:0x00080000
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:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893
Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 2a 0f 01 11 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9
RSP: 0018:ffffc9000442f018 EFLAGS: 00000206
RAX: 8a7b4dbb513bcf00 RBX: 0000000000000202 RCX: 8a7b4dbb513bcf00
RDX: 0000000000000002 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffff888034f2aa00 R08: ffffffff81ac149d R09: ffffffff8e13f2e0
R10: ffffc9000442f158 R11: ffffffff81ad9d50 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8e13f2e0 R15: ffff888034f29e80
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]
is_module_text_address+0x18b/0x1e0 kernel/module/main.c:3858
kernel_text_address+0x94/0xe0 kernel/extable.c:119
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2505
shmem_alloc_folio mm/shmem.c:1902 [inline]
shmem_alloc_and_add_folio+0x423/0xf40 mm/shmem.c:1944
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2568
shmem_get_folio mm/shmem.c:2674 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3bd538e1ff
RSP: 002b:00007f3bd6289df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f3bd538e1ff
RDX: 0000000001000000 RSI: 00007f3bcb000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009756
R10: 000020000001c602 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f3bd6289ef0 R14: 00007f3bd6289eb0 R15: 00007f3bcb000000
rcu: rcu_preempt kthread starved for 651 jiffies! g45261 f0x2 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:27032 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:
CPU: 0 UID: 0 PID: 61 Comm: kworker/u8:4 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:unwind_next_frame+0x18d/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: d8 48 c1 e8 03 48 89 44 24 28 0f b6 04 28 84 c0 0f 85 4c 1b 00 00 4c 89 6c 24 48 4c 89 64 24 20 4c 89 7c 24 50 48 89 5c 24 18 <0f> b6 1b 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 10 74 08 4c 89 ff
RSP: 0018:ffffc90000006838 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc9000000693d RCX: 64d101da761cb700
RDX: 000000007f45ee1d RSI: ffffffff8be07940 RDI: ffffffff8be07900
RBP: dffffc0000000000 R08: ffffffff81742f85 R09: ffffffff8e13f2e0
R10: ffffc90000006958 R11: ffffffff81ad9d50 R12: 1ffff92000000d21
R13: ffffc90000006958 R14: ffffc90000006908 R15: ffffffff81742f85
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a57f63e80 CR3: 000000007f09c000 CR4: 00000000003526f0
Call Trace:
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
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:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5274
dst_alloc+0x105/0x170 net/core/dst.c:89
rt_dst_alloc net/ipv4/route.c:1651 [inline]
__mkroute_output net/ipv4/route.c:2655 [inline]
ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2875
ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2705
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2932
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x6c4/0xf10 net/ipv4/netfilter.c:53
synproxy_send_tcp+0x3a7/0x700 net/netfilter/nf_synproxy_core.c:431
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+0xc5/0x220 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:6138 [inline]
__netif_receive_skb+0x143/0x380 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
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:480
blake2s_compress+0xe0/0x1e30 lib/crypto/x86/blake2s.h:42
blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:119
hmac+0x288/0x330 drivers/net/wireguard/noise.c:332
kdf drivers/net/wireguard/noise.c:367 [inline]
message_ephemeral+0x1e2/0x280 drivers/net/wireguard/noise.c:493
wg_noise_handshake_create_initiation+0x229/0x750 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+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