rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10000/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=43929, q=796132 ncpus=2)
task:syz.3.1125 state:R running task stack:26168 pid:10000 tgid:9998 ppid:5839 task_flags:0x400040 flags:0x00004002
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:unwind_next_frame+0x1734/0x2390 arch/x86/kernel/unwind_orc.c:648
Code: 31 be 33 11 01 4c 89 f7 e8 89 0c 00 00 e9 f7 01 00 00 48 8b 54 24 08 48 8d 5a 02 48 83 c2 03 48 89 d8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 19 0b 00 00 48 89 d0 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc9000adaf038 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff903bb3b8 RCX: 0000000000000000
RDX: ffffffff903bb3b9 RSI: 0000000000000001 RDI: ffffc9000adaf168
RBP: dffffc0000000000 R08: ffffc9000adaf167 R09: 0000000000000000
R10: ffffc9000adaf158 R11: fffff520015b5e2d R12: ffffc9000adafac0
R13: ffffc9000adaf158 R14: ffffc9000adaf108 R15: 1ffffffff2077677
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
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_mpol+0x232/0x4a0 mm/mempolicy.c:2419
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438
shmem_alloc_folio mm/shmem.c:1847 [inline]
shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1886
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2532
shmem_get_folio mm/shmem.c:2638 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3288
generic_perform_write+0x2c4/0x910 mm/filemap.c:4175
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3463
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x54b/0xa90 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/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3d0c58d3df
RSP: 002b:00007f3d0d342df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f3d0c58d3df
RDX: 0000000001000000 RSI: 00007f3d01e00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050ed
R10: 000020000000a2c2 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f3d0d342ef0 R14: 00007f3d0d342eb0 R15: 00007f3d01e00000
rcu: rcu_preempt kthread starved for 2747 jiffies! g43929 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:26792 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:
CPU: 1 UID: 0 PID: 6696 Comm: kworker/u8:36 Not tainted 6.16.0-rc4-next-20250703-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 eb 75 02 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a078f0 EFLAGS: 00000206
RAX: ae61d5bfe1afea00 RBX: 0000000000000202 RCX: ae61d5bfe1afea00
RDX: 0000000000000006 RSI: ffffffff8db8376b RDI: ffffffff8be32500
RBP: ffff88802dd7e5e0 R08: ffffc90000a07b50 R09: 0000000000000000
R10: ffffc90000a07a78 R11: fffff52000140f51 R12: 0000000000000006
R13: 0000000000000006 R14: ffffffff8e13bf60 R15: ffff88802dd7da00
FS: 0000000000000000(0000) GS:ffff888125d1e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe4555ed08 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
ref_tracker_alloc+0x17d/0x460 lib/ref_tracker.c:277
__netdev_tracker_alloc include/linux/netdevice.h:4344 [inline]
netdev_hold include/linux/netdevice.h:4373 [inline]
dst_init+0xd9/0x450 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:93
rt_dst_alloc net/ipv4/route.c:1645 [inline]
__mkroute_output net/ipv4/route.c:2646 [inline]
ip_route_output_key_hash_rcu+0x1482/0x23a0 net/ipv4/route.c:2867
ip_route_output_key_hash+0x1b9/0x2e0 net/ipv4/route.c:2697
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2924
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x6d2/0x1030 net/ipv4/netfilter.c:53
synproxy_send_tcp+0x359/0x6c0 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:157 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
__netif_receive_skb_one_core net/core/dev.c:5973 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6086
process_backlog+0x60e/0x14f0 net/core/dev.c:6438
__napi_poll+0xc4/0x480 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_update+0x1cb/0x450 lib/crypto/blake2s.c:40
blake2s include/crypto/blake2s.h:100 [inline]
compute_mac1+0x145/0x1a0 drivers/net/wireguard/cookie.c:80
wg_cookie_add_mac_to_packet+0x57/0x1a0 drivers/net/wireguard/cookie.c:163
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:35 [inline]
wg_packet_handshake_send_worker+0x17c/0x320 drivers/net/wireguard/send.c:51
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