rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7759/2:b..l
rcu: (detected by 0, t=10503 jiffies, g=21937, q=831983 ncpus=2)
task:syz.3.390 state:R running task stack:23352 pid:7759 tgid:7757 ppid:5826 task_flags:0x20400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7189
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 2b 6b d2 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003bce8f8 EFLAGS: 00000206
RAX: 2d88b6965c7ada00 RBX: 0000000000000000 RCX: 2d88b6965c7ada00
RDX: 0000000000000000 RSI: ffffffff8d960b2f RDI: ffffffff8bbf1b60
RBP: ffffffff81738f15 R08: 0000000000000000 R09: ffffffff81738f15
R10: ffffc90003bceab8 R11: ffffffff81ac55d0 R12: 0000000000000002
R13: ffffffff8df3d5a0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2500 [inline]
slab_free mm/slub.c:6630 [inline]
kmem_cache_free+0x4a2/0x690 mm/slub.c:6740
blk_update_request+0x57e/0xe60 block/blk-mq.c:998
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1160
nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1454 [inline]
null_queue_rq+0xbfe/0xe30 drivers/block/null_blk/main.c:1693
null_queue_rqs+0x123/0x270 drivers/block/null_blk/main.c:1707
__blk_mq_flush_list block/blk-mq.c:2837 [inline]
blk_mq_dispatch_queue_requests+0x417/0x800 block/blk-mq.c:2882
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2970
blk_add_rq_to_plug+0x175/0x450 block/blk-mq.c:1399
blk_mq_submit_bio+0x1a65/0x25b0 block/blk-mq.c:3222
__submit_bio+0x207/0x5a0 block/blk-core.c:637
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755
__block_write_full_folio+0x810/0xe10 fs/buffer.c:1933
blkdev_writepages+0xd1/0x170 block/fops.c:491
do_writepages+0x32e/0x550 mm/page-writeback.c:2604
filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
__filemap_fdatawrite_range mm/filemap.c:422 [inline]
filemap_write_and_wait_range+0x21f/0x320 mm/filemap.c:694
filemap_write_and_wait include/linux/pagemap.h:68 [inline]
sync_blockdev block/bdev.c:260 [inline]
bdev_release+0x192/0x650 block/bdev.c:1126
blkdev_release+0x15/0x20 block/fops.c:709
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
get_signal+0x11ec/0x1340 kernel/signal.c:2807
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc986d8efc9
RSP: 002b:00007fc987c48038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000000e00000 RBX: 00007fc986fe6090 RCX: 00007fc986d8efc9
RDX: 00000000fffffd2c RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007fc986e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc986fe6128 R14: 00007fc986fe6090 R15: 00007ffe7ccb9258
rcu: rcu_preempt kthread starved for 716 jiffies! g21937 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:27336 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
__schedule_loop kernel/sched/core.c:6944 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6959
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker
RIP: 0010:mark_usage kernel/locking/lockdep.c:4620 [inline]
RIP: 0010:__lock_acquire+0x5ec/0xd20 kernel/locking/lockdep.c:5191
Code: fe ff ff 44 89 e0 41 38 c5 76 1a e8 7e 5d ea 02 48 8b 3c 24 85 c0 74 0d 83 3d 33 1f e0 0d 00 0f 84 1a 05 00 00 83 7c 24 0c 00 <0f> 84 a9 00 00 00 41 8b 46 20 66 85 c0 0f 88 8d 00 00 00 65 8b 0d
RSP: 0018:ffffc90000a07868 EFLAGS: 00000046
RAX: 0000000000000003 RBX: 0000000000000007 RCX: 0000000000000007
RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff88801d2c5ac0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81738f15
R10: ffffc90000a07ab8 R11: ffffffff81ac55d0 R12: 0000000000000003
R13: 0000000000000001 R14: ffff88801d2c6708 R15: ffff88801d2c6728
FS: 0000000000000000(0000) GS:ffff888126022000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffac13db38 CR3: 0000000025042000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
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:4386 [inline]
netdev_hold include/linux/netdevice.h:4415 [inline]
dst_init+0xe6/0x460 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:93
rt_dst_alloc net/ipv4/route.c:1646 [inline]
__mkroute_output net/ipv4/route.c:2650 [inline]
ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2870
ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2700
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x6c4/0xf10 net/ipv4/netfilter.c:53
synproxy_send_tcp+0x3a7/0x700 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:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6126 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6239
process_backlog+0x60e/0x14f0 net/core/dev.c:6591
__napi_poll+0xc7/0x360 net/core/dev.c:7641
napi_poll net/core/dev.c:7704 [inline]
net_rx_action+0x5f7/0xdf0 net/core/dev.c:7831
handle_softirqs+0x286/0x870 kernel/softirq.c:622
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
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+0xe9/0x1b80 lib/crypto/x86/blake2s.h:44
blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:126
hmac+0x288/0x330 drivers/net/wireguard/noise.c:332
kdf+0x105/0x270 drivers/net/wireguard/noise.c:367
mix_dh drivers/net/wireguard/noise.c:413 [inline]
wg_noise_handshake_create_initiation+0x278/0x750 drivers/net/wireguard/noise.c:550
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline]
wg_packet_handshake_send_worker+0x163/0x320 drivers/net/wireguard/send.c:51
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245