rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=78177, q=596 ncpus=2)
task:kthreadd state:R running task stack:26096 pid:2 tgid:2 ppid:0 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893
Code: 8e 9d 11 00 00 00 00 eb b5 e8 e5 5e 11 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 d5 49 9d 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 92 0d 94
RSP: 0018:ffffc90000077108 EFLAGS: 00000282
RAX: d795de074a542c00 RBX: 0000000000000206 RCX: 0000000000000046
RDX: 0000000000000001 RSI: ffffffff8e25a5be RDI: ffffffff8c2a9f80
RBP: ffff88801d6d49c8 R08: ffffc90000077df8 R09: 0000000000000000
R10: ffffc90000077238 R11: fffff5200000ee49 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e959c20 R15: ffff88801d6d3e00
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
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:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
__slab_free+0x274/0x2c0 mm/slub.c:5767
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_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959
alloc_pid+0x1ae/0x1310 kernel/pid.c:188
copy_process+0x2145/0x43f0 kernel/fork.c:2304
kernel_clone+0x2d7/0x940 kernel/fork.c:2747
kernel_thread+0x13f/0x1b0 kernel/fork.c:2808
create_kthread kernel/kthread.c:459 [inline]
kthreadd+0x4ec/0x6e0 kernel/kthread.c:817
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: rcu_preempt kthread starved for 10313 jiffies! g78177 f0x0 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:28192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17382 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67
Code: 89 e7 e8 b3 e1 bc 00 e9 1e fd ff ff 66 66 66 66 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 <48> 8b 07 c3 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90
RSP: 0018:ffffc90000006b78 EFLAGS: 00000202
RAX: ffffc90000007401 RBX: 1ffff92000000d86 RCX: 1ffff92000000d01
RDX: ffffc90000007438 RSI: 0000000000000002 RDI: ffffc90000007438
RBP: 1ffffffff22b98f1 R08: ffffc90000007440 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e959c20 R12: 1ffff92000000d87
R13: ffffc90000008000 R14: ffffc90000006c28 R15: ffffc90000000000
FS: 0000000000000000(0000) GS:ffff888125226000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561cd2ceba38 CR3: 0000000011c5c000 CR4: 00000000003526f0
Call Trace:
deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
unwind_next_frame+0xca5/0x2550 arch/x86/kernel/unwind_orc.c:614
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2705 [inline]
slab_free mm/slub.c:6405 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6532
skb_ext_reset include/linux/skbuff.h:5117 [inline]
skb_release_head_state+0x270/0x360 net/core/skbuff.c:1183
skb_release_all net/core/skbuff.c:1189 [inline]
__kfree_skb+0x24/0x210 net/core/skbuff.c:1205
kfree_skb_reason include/linux/skbuff.h:1323 [inline]
kfree_skb include/linux/skbuff.h:1332 [inline]
dst_discard_out+0x1c/0x30 net/core/dst.c:32
ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
__netif_receive_skb_one_core net/core/dev.c:6206 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
netif_receive_skb_internal net/core/dev.c:6405 [inline]
netif_receive_skb+0x278/0xbf0 net/core/dev.c:6464
NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318
br_handle_frame_finish+0x1192/0x1990 net/bridge/br_input.c:-1
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
process_backlog+0x706/0x1860 net/core/dev.c:6670
__napi_poll+0xaa/0x330 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7949
handle_softirqs+0x225/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
blake2s_compress+0xfa/0x1c00 lib/crypto/x86/blake2s.h:42
blake2s_final+0x10f/0x270 lib/crypto/blake2s.c:142
hmac+0x204/0x3b0 drivers/net/wireguard/noise.c:325
kdf+0x12d/0x290 drivers/net/wireguard/noise.c:367
mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline]
wg_noise_handshake_create_initiation+0x460/0x810 drivers/net/wireguard/noise.c:560
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:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 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