rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20433/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=70445, q=2522 ncpus=2)
task:syz.3.5006 state:R running task stack:25208 pid:20433 tgid:20432 ppid:14923 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:____bpf_ringbuf_output kernel/bpf/ringbuf.c:623 [inline]
RIP: 0010:bpf_ringbuf_output+0x53/0x1f0 kernel/bpf/ringbuf.c:613
Code: ff db ff 48 83 fb 04 0f 83 62 01 00 00 49 bd 00 00 00 00 00 fc ff df 49 81 c4 e8 01 00 00 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 83 35 47 00 49 8b 3c 24 4c 89 f6 e8 f7 14 00 00
RSP: 0018:ffffc9000575fa70 EFLAGS: 00000246
RAX: 1ffff1100864603d RBX: 0000000000000000 RCX: ffff8880555bbd80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000004
RBP: ffffc9000575fab8 R08: ffffc9000575fc57 R09: 0000000000000000
R10: ffffc9000575fc20 R11: ffffffffa0209564 R12: ffff8880432301e8
R13: dffffc0000000000 R14: 0000000000000008 R15: ffffc9000575fab0
bpf_prog_47c242b8da294cd2+0x4b/0x53
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:722 [inline]
bpf_prog_run include/linux/filter.h:729 [inline]
bpf_prog_run_pin_on_cpu include/linux/filter.h:746 [inline]
bpf_flow_dissect+0x224/0x730 net/core/flow_dissector.c:1024
bpf_prog_test_run_flow_dissector+0x3a4/0x610 net/bpf/test_run.c:1525
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4742
__sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6266
__do_sys_bpf kernel/bpf/syscall.c:6361 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6359 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6359
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f62d739cdd9
RSP: 002b:00007f62d81ee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f62d7615fa0 RCX: 00007f62d739cdd9
RDX: 0000000000000050 RSI: 0000200000000240 RDI: 000000000000000a
RBP: 00007f62d7432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62d7616038 R14: 00007f62d7615fa0 R15: 00007ffdd0b576a8
rcu: rcu_preempt kthread starved for 1003 jiffies! g70445 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
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: 0 UID: 0 PID: 9009 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:753
Code: 89 f7 e8 5c 23 86 00 48 c7 c3 d8 c9 3a 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 89 b8 8e 11 <74> 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 cc cc cc cc cc e8 b1 c3
RSP: 0018:ffffc90000006d58 EFLAGS: 00000282
RAX: 0000000000049ae4 RBX: ffff8880b86339d8 RCX: 0000000080000102
RDX: 00000000a42637f2 RSI: ffffffff8c28adc0 RDI: ffffffff8c28ad80
RBP: dffffc0000000000 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: ffffc90000006e98 R11: ffffffff81b0e910 R12: ffffc90000006e80
R13: 1ffff92000000dc9 R14: ffffffff8e267790 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125287000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2bd77e8158 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd5/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950
kmalloc_reserve net/core/skbuff.c:613 [inline]
__alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack+0x172/0xe30 net/netfilter/nf_synproxy_core.c:461
nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1ae0 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:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7950
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
neigh_periodic_work+0xc28/0xe50 net/core/neighbour.c:1038
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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