rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5716/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=80809, q=1597 ncpus=2)
task:kworker/0:4 state:R running task stack:22152 pid:5716 tgid:5716 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline]
RIP: 0010:gc_worker+0x2bb/0x1630 net/netfilter/nf_conntrack_core.c:1545
Code: 00 00 48 c7 c7 c8 60 d8 90 e8 d1 56 35 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 8f 6d 59 f8 58 48 85 db 0f 85 97 0f 00 00 a0 72 59 f8 8b 1d 7a 2c 29 07 89 dd 31 ff 83 e5 01 89 ee e8 3c
RSP: 0018:ffffc90003c7fb40 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89af3ed6
RDX: ffff888034972500 RSI: ffffffff89af3ee5 RDI: ffff888034972500
RBP: 000000000000bc27 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000040000 R14: 0000000000005e14 R15: 00000000000017a8
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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 375 jiffies! g80809 f0x0 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:27992 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 1168 Comm: kworker/u8:9 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:xt_get_this_cpu_counter include/linux/netfilter/x_tables.h:434 [inline]
RIP: 0010:xt_get_this_cpu_counter include/linux/netfilter/x_tables.h:431 [inline]
RIP: 0010:ipt_do_table+0xfc3/0x1b00 net/ipv4/netfilter/ip_tables.c:297
Code: 8d 3c e5 20 49 1d 8e 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 21 09 00 00 4a 03 1c e5 20 49 1d 8e d9 fa ff ff 48 89 54 24 28 e8 ae 05 eb f7 48 8b 54 24 28 48 b8
RSP: 0018:ffffc90000a081b8 EFLAGS: 00000282
RAX: dffffc0000000000 RBX: ffffe8ffffd98010 RCX: ffffffff8a1d9bef
RDX: 1ffffffff1c3a925 RSI: ffffffff8c1c3780 RDI: ffffffff8e1d4928
RBP: ffff888074caf130 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000001 R14: ffff888074caf0d8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888124472000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb268a00218 CR3: 000000003505a000 CR4: 00000000003526f0
Call Trace:
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
__ip_local_out+0x541/0xb80 net/ipv4/ip_output.c:120
ip_local_out+0x2a/0x1f0 net/ipv4/ip_output.c:129
synproxy_send_tcp.isra.0+0x481/0x680 net/netfilter/nf_synproxy_core.c:440
synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:485
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
nft_synproxy_do_eval+0xa6a/0xd50 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e5/0x1990 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262
dst_input include/net/dst.h:480 [inline]
ip_rcv_finish net/ipv4/ip_input.c:492 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6202
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6315
process_backlog+0x37a/0x1580 net/core/dev.c:6666
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7950
handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline]
nsim_dev_trap_report_work+0x8d6/0xd20 drivers/net/netdevsim/dev.c:922
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245