rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=32049, q=2679386 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 9390 (4294966893-4294957503), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 9390 jiffies! g32049 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:25552 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 5229 Comm: kworker/1:3 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:rcu_stall_kick_kthreads+0xa/0x240 kernel/rcu/tree_stall.h:203 Code: f3 0f 1e fa e9 77 08 ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 53 80 3d 96 1e c5 18 00 <0f> 84 60 01 00 00 48 8b 1d 09 fd 17 0d 48 c7 c0 00 f2 60 8e 48 c1 RSP: 0000:ffffc90000a171e8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880b8700000 RCX: ffffffff817ad765 RDX: 0000000000000000 RSI: ffffffff8c60f840 RDI: ffffffff8c60f800 RBP: ffffc90000a172c8 R08: ffffffff901ce66f R09: 1ffffffff2039ccd R10: dffffc0000000000 R11: fffffbfff2039cce R12: ffff8880b873fa58 R13: ffff8880b873fa40 R14: 1ffff110170e7f4b R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fef63716a CR3: 00000000289fa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_cpu_stall kernel/rcu/tree_stall.h:752 [inline] rcu_pending kernel/rcu/tree.c:4417 [inline] rcu_sched_clock_irq+0x5ae/0x10d0 kernel/rcu/tree.c:2668 update_process_times+0x1ce/0x230 kernel/time/timer.c:2519 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x37c/0x500 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1026 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1043 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x6a4/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: 09 00 00 4c 89 7c 24 28 48 8b 44 24 58 42 80 3c 20 00 74 08 4c 89 f7 e8 2a 30 bd 00 49 8b 2e e9 32 02 00 00 4d 89 ec 4d 89 ee <48> 89 e8 4c 29 f0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 RSP: 0000:ffffc90000a176d0 EFLAGS: 00000293 RAX: ffffffff9035bf28 RBX: ffffffff9035bf2c RCX: ffffffff9035bf30 RDX: 00000000000b0001 RSI: ffffffff90af4672 RDI: 0000000000000001 RBP: ffffffff9035bf54 R08: 0000000000000014 R09: ffffc90000a17890 R10: ffffc90000a177f0 R11: ffffffff81808f50 R12: ffffffff9035bf2c R13: ffffffff9035bf08 R14: ffffffff9035bf30 R15: ffffffff81fe58b5 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 dst_alloc+0x12b/0x190 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1612 [inline] __mkroute_output net/ipv4/route.c:2573 [inline] ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2795 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2624 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2852 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x80d/0x1300 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x356/0x6c0 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 neigh_periodic_work+0xb35/0xd50 net/core/neighbour.c:1019 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244