rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P28614/1:b..l P28637/3:b..l
rcu: (detected by 1, t=10504 jiffies, g=400757, q=613275 ncpus=2)
task:syz.2.22812 state:R running task stack:26744 pid:28637 tgid:28633 ppid:24809 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7409
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline]
__dev_queue_xmit+0x1ed7/0x37f0 net/core/dev.c:4907
dev_queue_xmit include/linux/netdevice.h:3436 [inline]
neigh_hh_output include/net/neighbour.h:544 [inline]
neigh_output include/net/neighbour.h:558 [inline]
ip_finish_output2+0xbda/0x10b0 net/ipv4/ip_output.c:236
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:437
__ip_queue_xmit+0x10df/0x1b10 net/ipv4/ip_output.c:533
__tcp_transmit_skb+0x2d18/0x47c0 net/ipv4/tcp_output.c:1717
tcp_transmit_skb net/ipv4/tcp_output.c:1734 [inline]
tcp_connect+0x220b/0x53e0 net/ipv4/tcp_output.c:4375
tcp_v4_connect+0x1051/0x1950 net/ipv4/tcp_ipv4.c:345
__inet_stream_connect+0x258/0xe00 net/ipv4/af_inet.c:684
inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:755
__sys_connect_file net/socket.c:2135 [inline]
__sys_connect+0x323/0x460 net/socket.c:2154
__do_sys_connect net/socket.c:2160 [inline]
__se_sys_connect net/socket.c:2157 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2157
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9bff19ce59
RSP: 002b:00007f9c0009c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f9bff416180 RCX: 00007f9bff19ce59
RDX: 0000000000000010 RSI: 0000200000000180 RDI: 0000000000000009
RBP: 00007f9bff232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9bff416218 R14: 00007f9bff416180 R15: 00007ffc0477c478
task:syz.5.22808 state:R running task stack:26136 pid:28614 tgid:28607 ppid:25092 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552
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:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217
Code: d8 49 74 11 65 8b 15 f9 49 74 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 17 00 00 00 74 2c 8b 91 f8 16 00 00 <83> fa 02 75 21 48 8b 91 00 17 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc9000666f9b8 EFLAGS: 00000246
RAX: ffffffff8215a2c7 RBX: 0000000000000000 RCX: ffff888052d0be00
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000666fac0 R08: ffff88805384c3c3 R09: 1ffff1100a709878
R10: dffffc0000000000 R11: ffffed100a709879 R12: dffffc0000000000
R13: ffffea0002ba88c0 R14: ffffea0002ba88c0 R15: 0000000000000000
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
pte_unmap include/linux/pgtable.h:117 [inline]
follow_page_pte+0xb67/0xe70 mm/gup.c:889
follow_pmd_mask mm/gup.c:-1 [inline]
follow_pud_mask mm/gup.c:967 [inline]
follow_p4d_mask mm/gup.c:984 [inline]
follow_page_mask mm/gup.c:1023 [inline]
__get_user_pages+0xa74/0x2720 mm/gup.c:1426
populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
__mm_populate+0x25f/0x390 mm/gup.c:1963
mm_populate include/linux/mm.h:4137 [inline]
vm_mmap_pgoff+0x353/0x4e0 mm/util.c:586
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9f3af9ce59
RSP: 002b:00007f9f3be3e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f9f3b216180 RCX: 00007f9f3af9ce59
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f9f3b032e6f R08: ffffffffffffffff R09: 00000000fdffa000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f3b216218 R14: 00007f9f3b216180 R15: 00007ffe9eabb958
rcu: rcu_preempt kthread starved for 242 jiffies! g400757 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:28040 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
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:
CPU: 1 UID: 0 PID: 15615 Comm: kworker/u8:50 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:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:unwind_next_frame+0x1a18/0x2550 arch/x86/kernel/unwind_orc.c:694
Code: 50 0f 85 63 01 00 00 48 8b 44 24 38 80 3c 18 00 74 09 49 8d 7e 38 e8 27 8f ba 00 4d 8b 7e 38 49 8d 7e 08 48 89 f8 48 c1 e8 03 <80> 3c 18 00 74 05 e8 0d 8f ba 00 4d 8b 66 08 49 8d 5e 10 48 89 d8
RSP: 0018:ffffc90000a07b60 EFLAGS: 00000a06
RAX: 1ffff92000140f82 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffffc90000a07c48 RSI: dffffc0000000000 RDI: ffffc90000a07c10
RBP: 1ffffffff2298d01 R08: ffffc90000a07ef8 R09: 0000000000000000
R10: ffffc90000a07c58 R11: fffff52000140f8d R12: dffffc0000000000
R13: ffffffff8176a21f R14: ffffc90000a07c08 R15: ffffc90000a07f08
FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558ada594e68 CR3: 0000000087df4000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
ref_tracker_alloc+0x1b0/0x4b0 lib/ref_tracker.c:276
__netdev_tracker_alloc include/linux/netdevice.h:4489 [inline]
netdev_hold include/linux/netdevice.h:4518 [inline]
dst_init+0xbe/0x470 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:94
rt_dst_alloc net/ipv4/route.c:1649 [inline]
__mkroute_output net/ipv4/route.c:2652 [inline]
ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2872
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2702
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2929
ip_route_output_key include/net/route.h:179 [inline]
ip_route_me_harder+0x762/0xfe0 net/ipv4/netfilter.c:54
synproxy_send_tcp+0x347/0x670 net/netfilter/nf_synproxy_core.c:434
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487
nft_synproxy_eval_v4+0x37b/0x530 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
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
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6206 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
process_backlog+0xa34/0x1860 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/0x260 lib/crypto/blake2s.c:142
hmac+0x2dc/0x3b0 drivers/net/wireguard/noise.c:333
kdf drivers/net/wireguard/noise.c:360 [inline]
message_ephemeral+0x233/0x310 drivers/net/wireguard/noise.c:493
wg_noise_handshake_create_initiation+0x24f/0x810 drivers/net/wireguard/noise.c:545
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:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
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