rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P38/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=36869, q=434163 ncpus=2)
task:khugepaged state:R running task stack:26168 pid:38 tgid:38 ppid:2 task_flags:0x200040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5318 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6701
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7024
irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:873 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
RIP: 0010:unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
Code: 5a 0e 01 48 c7 c7 00 31 a8 8b be 66 03 00 00 48 c7 c2 a0 31 a8 8b e8 36 1c 2b 00 48 c7 c7 60 bf 53 8e 4c 89 fe e8 17 02 2b 00 c2 9d 34 00 89 d8 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc90000ae6dd8 EFLAGS: 00000286
RAX: 5d7756e7de470100 RBX: ffffffff90808f01 RCX: 5d7756e7de470100
RDX: 0000000000000000 RSI: ffffffff8de74275 RDI: ffffffff8c04be80
RBP: dffffc0000000000 R08: ffffc90000ae7290 R09: 0000000000000000
R10: ffffc90000ae6ef8 R11: fffff5200015cde1 R12: ffffc90000ae72a0
R13: ffffc90000ae0000 R14: ffffc90000ae6ea8 R15: ffffffff8172ec65
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
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4396
kmalloc_noprof include/linux/slab.h:905 [inline]
add_stack_record_to_list mm/page_owner.c:172 [inline]
inc_stack_record_count mm/page_owner.c:214 [inline]
__set_page_owner+0x25c/0x4a0 mm/page_owner.c:333
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1848
prep_new_page mm/page_alloc.c:1856 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3855
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5145
__alloc_pages_noprof mm/page_alloc.c:5179 [inline]
__folio_alloc_noprof+0x18/0x120 mm/page_alloc.c:5189
alloc_charge_folio+0x3c7/0x830 mm/khugepaged.c:1069
collapse_huge_page mm/khugepaged.c:1113 [inline]
hpage_collapse_scan_pmd+0x120c/0x3ad0 mm/khugepaged.c:1417
khugepaged_scan_mm_slot mm/khugepaged.c:2452 [inline]
khugepaged_do_scan mm/khugepaged.c:2539 [inline]
khugepaged+0x986/0x1690 mm/khugepaged.c:2595
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 1267 jiffies! g36869 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:26632 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5318 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6701
__schedule_loop kernel/sched/core.c:6779 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6794
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2060
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2262
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/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: 48 Comm: kworker/1:1 Not tainted 6.16.0-rc4-next-20250704-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
RIP: 0010:memset_orig+0x15/0xb0 arch/x86/lib/memset_64.S:57
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af c1 <41> 89 f9 41 83 e1 07 75 74 48 89 d1 48 c1 e9 06 74 39 66 0f 1f 84
RSP: 0018:ffffc90000a07c10 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffc90000a07d20 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000a07d38
RBP: dffffc0000000000 R08: ffffc90000a07d47 R09: 1ffff92000140fa8
R10: ffffc90000a07d38 R11: fffff52000140fa9 R12: ffffc90000b87820
R13: ffffc90000a07d38 R14: ffffc90000a07ce8 R15: ffffc90000a07d30
FS: 0000000000000000(0000) GS:ffff8881258af000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f051e800218 CR3: 000000007033a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592
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:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
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:660
alloc_skb include/linux/skbuff.h:1336 [inline]
synproxy_send_client_synack_ipv6+0x169/0xca0 net/netfilter/nf_synproxy_core.c:873
nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90
nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x409/0x1920 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:157 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
__netif_receive_skb_one_core net/core/dev.c:5973 [inline]
__netif_receive_skb+0xd3/0x380 net/core/dev.c:6086
process_backlog+0x60e/0x14f0 net/core/dev.c:6438
__napi_poll+0xc7/0x480 net/core/dev.c:7451
napi_poll net/core/dev.c:7515 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7642
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_final+0x116/0x260 lib/crypto/blake2s.c:55
hmac+0x293/0x330 drivers/net/wireguard/noise.c:333
kdf drivers/net/wireguard/noise.c:360 [inline]
message_ephemeral+0x1c0/0x280 drivers/net/wireguard/noise.c:493
wg_noise_handshake_consume_initiation+0x1cb/0x900 drivers/net/wireguard/noise.c:605
wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline]
wg_packet_handshake_receive_worker+0x5f2/0xfb0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245