rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8372/1:b..l..
rcu: (detected by 0, t=10503 jiffies, g=35789, q=1869 ncpus=2)
task:syz.4.491 state:R running task stack:25464 pid:8372 tgid:8371 ppid:5629 task_flags:0x480140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline]
irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947
Code: ff ff ff e8 20 3e 51 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 32 68 f5 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 cf 50 54 0a cc 48 8d 3d 87 dc d9
RSP: 0018:ffffc900062672c0 EFLAGS: 00000296
RAX: c6e92a8c47dccc00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000aabd21bb RSI: ffffffff8e6f7dc2 RDI: ffffffff8c6e6780
RBP: ffff888035708000 R08: ffffffff817859cf R09: 0000000000000000
R10: ffffc900062673f8 R11: ffffffff81b37250 R12: ffffffff8fd5a420
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:183
__reset_page_owner+0x73/0x2a0 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1401 [inline]
__free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2952
__slab_free+0x269/0x2c0 mm/slub.c:5926
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_kmalloc+0x22/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
kobject_uevent_env+0x289/0x9e0 lib/kobject_uevent.c:543
device_del+0x74d/0x8f0 drivers/base/core.c:3983
device_unregister+0x21/0xf0 drivers/base/core.c:4006
bdi_unregister+0x43e/0x530 mm/backing-dev.c:1174
generic_shutdown_super+0x238/0x2d0 fs/super.c:791
kill_anon_super+0x3b/0x70 fs/super.c:1355
v9fs_kill_super+0x41/0x80 fs/9p/vfs_super.c:172
deactivate_locked_super+0xbe/0x110 fs/super.c:586
v9fs_get_tree+0x84a/0xac0 fs/9p/vfs_super.c:156
vfs_get_tree+0x92/0x2a0 fs/super.c:1943
fc_mount fs/namespace.c:1282 [inline]
do_new_mount_fc fs/namespace.c:3910 [inline]
do_new_mount+0x325/0xb00 fs/namespace.c:3986
do_mount fs/namespace.c:4350 [inline]
__do_sys_mount fs/namespace.c:4565 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4542
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffb2ed9e559
RSP: 002b:00007ffb2fbc3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffb2f025fa0 RCX: 00007ffb2ed9e559
RDX: 0000200000000840 RSI: 00002000000006c0 RDI: 0000000000000000
RBP: 00007ffb2ee35ab8 R08: 0000200000000880 R09: 0000000000000000
R10: 0000000000800800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffb2f026038 R14: 00007ffb2f025fa0 R15: 00007ffc61d307e8
rcu: rcu_preempt kthread starved for 448 jiffies! g35789 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6132 Comm: kworker/u8:15 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:in_softirq_really kernel/kcov.c:167 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:179 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:252 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x8c/0x120 kernel/kcov.c:365
Code: 84 a3 00 00 00 4e 8b 54 ce 10 65 4c 8b 1d 6c 71 d0 12 41 f7 c3 00 01 00 ff 74 2c 44 89 db 81 e3 00 01 00 0f 81 fb 00 01 00 00 <0f> 95 c3 41 81 fb 00 00 00 10 41 0f 93 c3 41 08 db 75 bc 41 83 b8
RSP: 0018:ffffc90000a37958 EFLAGS: 00000246
RAX: 000000000000000e RBX: 0000000000000100 RCX: 0000000000000001
RDX: ffffffff89be4748 RSI: ffffffff91253770 RDI: 0000000000000006
RBP: ffffc90000a37f98 R08: ffff88807eaa9f40 R09: 0000000000000008
R10: 0000000000000032 R11: 8000000000000101 R12: ffffffff8e762058
R13: fffff52000146f60 R14: 1ffff1103a9875d8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888123b8b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558cb914e8 CR3: 000000000fb48000 CR4: 00000000003526f0
Call Trace:
__skb_flow_dissect+0x3168/0x6da0 net/core/flow_dissector.c:1543
__xfrm_decode_session+0xf0/0xb80 net/xfrm/xfrm_policy.c:3519
xfrm_decode_session include/net/xfrm.h:1357 [inline]
ip_route_me_harder+0x9fd/0xfe0 net/ipv4/netfilter.c:67
synproxy_send_tcp+0x332/0x670 net/netfilter/nf_synproxy_core.c:434
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487
nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x389/0x5d0 net/netfilter/nft_synproxy.c:142
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:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:633
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6405 [inline]
__netif_receive_skb net/core/dev.c:6518 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6869
__napi_poll+0xaa/0x330 net/core/dev.c:7938
napi_poll net/core/dev.c:8001 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8158
handle_softirqs+0x265/0x8d0 kernel/softirq.c:669
do_softirq+0x77/0xd0 kernel/softirq.c:569
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
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+0xff/0x290 drivers/net/wireguard/noise.c:360
mix_dh drivers/net/wireguard/noise.c:413 [inline]
wg_noise_handshake_create_initiation+0x29e/0x810 drivers/net/wireguard/noise.c:550
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:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
kthread+0x38b/0x480 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