rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23024/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=126909, q=729 ncpus=2)
task:syz.4.4003 state:R running task stack:25416 pid:23024 tgid:23023 ppid:5806 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7234
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:get_current arch/x86/include/asm/current.h:23 [inline]
RIP: 0010:write_comp_data+0x10/0x90 kernel/kcov.c:245
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 79 f8 04 12 49 89 f8 49 89 f1 49 89 d2 <65> 48 8b 3d 50 f8 04 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00
RSP: 0018:ffffc900037eee70 EFLAGS: 00000202
RAX: 0000000080000000 RBX: ffff88801d66c028 RCX: ffffffff82802efd
RDX: 000000000000000b RSI: 0000000000000010 RDI: 0000000000000007
RBP: ffff88801d66c000 R08: 0000000000000007 R09: 0000000000000010
R10: 000000000000000b R11: 0000000000000000 R12: 000000000000000b
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000001
sized_strscpy include/linux/fortify-string.h:319 [inline]
__update_page_owner_handle+0x15d/0x550 mm/page_owner.c:265
__set_page_owner+0x11f/0x540 mm/page_owner.c:342
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2484
folio_alloc_mpol_noprof+0x36/0x340 mm/mempolicy.c:2503
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1930
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1972
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2567
shmem_fault+0x1f9/0xa20 mm/shmem.c:2768
__do_fault+0x10d/0x550 mm/memory.c:5363
do_read_fault mm/memory.c:5798 [inline]
do_fault+0xaf9/0x1950 mm/memory.c:5932
do_pte_missing mm/memory.c:4477 [inline]
handle_pte_fault mm/memory.c:6316 [inline]
__handle_mm_fault+0x180f/0x2b60 mm/memory.c:6454
handle_mm_fault+0x36d/0xa20 mm/memory.c:6623
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0xf9c/0x34d0 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x107/0x3a0 mm/gup.c:1963
mm_populate include/linux/mm.h:3899 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0xe1/0x650 mm/mmap.c:605
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc3799c799
RSP: 002b:00007fbc3889c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fbc37c15fa0 RCX: 00007fbc3799c799
RDX: b635773f06ebbee2 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fbc37a32bd9 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc37c16038 R14: 00007fbc37c15fa0 R15: 00007ffcdff1ba28
rcu: rcu_preempt kthread starved for 7625 jiffies! g126909 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:28968 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 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: 17067 Comm: kworker/1:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:debug_check_no_locks_freed+0x69/0x120 kernel/locking/lockdep.c:6731
Code: 4c 8d 24 37 48 8b 43 10 48 8d 50 28 48 39 d5 73 36 4c 39 e0 73 31 e8 66 b8 0d 03 85 c0 74 0a 8b 05 ac 39 f5 0e 85 c0 74 30 9c <58> f6 c4 02 75 22 41 f7 c6 00 02 00 00 74 01 fb 5b 5d 41 5c 41 5d
RSP: 0018:ffffc90000a084b8 EFLAGS: 00000046
RAX: ffffffff8e7e93e0 RBX: ffff88802a413060 RCX: ffff88802a413060
RDX: ffffffff8e7e9408 RSI: 00000000000002c0 RDI: ffff8881d0694d00
RBP: ffff8881d0694d00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d0694fc0
R13: ffff88802a412480 R14: 0000000000000202 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124447000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8b19e12f0 CR3: 0000000036288000 CR4: 00000000003526f0
Call Trace:
slab_free_hook mm/slub.c:2620 [inline]
slab_free mm/slub.c:6143 [inline]
kmem_cache_free+0xb5/0x6a0 mm/slub.c:6273
skb_kfree_head net/core/skbuff.c:1087 [inline]
skb_kfree_head net/core/skbuff.c:1084 [inline]
skb_free_head+0x1c6/0x220 net/core/skbuff.c:1101
skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128
skb_release_all net/core/skbuff.c:1203 [inline]
__kfree_skb net/core/skbuff.c:1217 [inline]
consume_skb net/core/skbuff.c:1450 [inline]
consume_skb+0xc4/0x110 net/core/skbuff.c:1444
nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:92 [inline]
nft_synproxy_do_eval+0x949/0xd50 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e8/0x1930 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xee/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:500
dst_input include/net/dst.h:480 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0x261/0x610 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6167
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6280
process_backlog+0x37a/0x1580 net/core/dev.c:6631
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7695
napi_poll net/core/dev.c:7758 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7910
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
wg_socket_send_skb_to_peer+0x145/0x210 drivers/net/wireguard/socket.c:184
wg_socket_send_buffer_to_peer+0x148/0x1a0 drivers/net/wireguard/socket.c:200
wg_packet_send_handshake_response+0x298/0x310 drivers/net/wireguard/send.c:103
wg_receive_handshake_packet+0x7dd/0xc20 drivers/net/wireguard/receive.c:154
wg_packet_handshake_receive_worker+0x15e/0x370 drivers/net/wireguard/receive.c:213
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245