syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=34653, q=1654564 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4295040332-4295029831), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g34653 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:25880 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 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
 </TASK>
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: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc3-syzkaller-00044-gaef25be35d23 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:stack_trace_consume_entry+0x0/0x280 kernel/stacktrace.c:83
Code: 17 78 00 e9 6a ff ff ff e8 1d 60 35 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 fb 48
RSP: 0018:ffffc90000a17a78 EFLAGS: 00000286
RAX: ffffffff810a47aa RBX: ffffc90000a17a80 RCX: ffffffff91773000
RDX: ffffffff91922001 RSI: ffffffff810a47aa RDI: ffffc90000a17b60
RBP: ffffc90000a17b10 R08: ffffc900001e7de0 R09: 0000000000000000
R10: ffffc90000a17ad0 R11: ffffffff818b3990 R12: ffff88801d6f0000
R13: ffffffff818b3990 R14: ffffc90000a17b60 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35c7bd CR3: 0000000064648000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 arch_stack_walk+0x10e/0x150 arch/x86/kernel/stacktrace.c:27
 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:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1323 [inline]
 synproxy_send_client_synack+0x1b9/0xe20 net/netfilter/nf_synproxy_core.c:460
 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:5672 [inline]
 __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5785
 process_backlog+0x662/0x15b0 net/core/dev.c:6117
 __napi_poll+0xcb/0x490 net/core/dev.c:6883
 napi_poll net/core/dev.c:6952 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7074
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 __do_softirq kernel/softirq.c:595 [inline]
 invoke_softirq kernel/softirq.c:435 [inline]
 __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:raw_spin_rq_unlock_irq+0x19/0x90 kernel/sched/sched.h:1536
Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 48 89 fb 66 90 48 89 df e8 5e a2 53 0a e8 e9 85 37 00 fb 5b <41> 5e 41 5f c3 cc cc cc cc f3 0f 1e fa 49 bf 00 00 00 00 00 fc ff
RSP: 0018:ffffc900001e7b08 EFLAGS: 00000286
RAX: 705f362794445b00 RBX: ffff8880b873e740 RCX: ffffffff81a73c8c
RDX: dffffc0000000000 RSI: ffffffff8c5ed880 RDI: ffffffff816fb7a7
RBP: ffffc900001e7d30 R08: ffffffff90184fb7 R09: 1ffffffff20309f6
R10: dffffc0000000000 R11: fffffbfff20309f7 R12: ffffc900001e7cb0
R13: 1ffff110170e7ea9 R14: ffff88801d6f0000 R15: ffff88801d6f0770
 __schedule+0x19b4/0x4be0 kernel/sched/core.c:6760
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6935
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6959
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 smpboot_thread_fn+0x65b/0xa30 kernel/smpboot.c:163
 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
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc3-syzkaller-00044-gaef25be35d23 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:__skb_insert include/linux/skbuff.h:2272 [inline]
RIP: 0010:__skb_queue_before include/linux/skbuff.h:2378 [inline]
RIP: 0010:__skb_queue_tail include/linux/skbuff.h:2411 [inline]
RIP: 0010:enqueue_to_backlog+0x860/0xc80 net/core/dev.c:4891
Code: f8 48 8b 44 24 08 49 89 45 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 48 8b 6c 24 28 74 08 4c 89 f7 e8 e5 4e 76 f8 48 8b 44 24 08 <49> 89 06 48 8b 44 24 60 42 0f b6 04 38 84 c0 0f 85 58 01 00 00 ff
RSP: 0018:ffffc900001e66b0 EFLAGS: 00000046
RAX: ffff8880ab076500 RBX: ffff8880ab076508 RCX: ffff88801d6f0000
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff8880b873fe40 R08: ffffffff898d0290 R09: 1ffff110170e800b
R10: dffffc0000000000 R11: ffffed10170e800c R12: ffff8880ab076500
R13: ffff8880b873fff8 R14: ffff8880b873fff0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35c7bd CR3: 0000000064648000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 netif_rx_internal+0x17a/0x630 net/core/dev.c:5201
 __netif_rx+0x78/0xc0 net/core/dev.c:5221
 loopback_xmit+0x454/0x6b0 drivers/net/loopback.c:89
 __netdev_start_xmit include/linux/netdevice.h:5002 [inline]
 netdev_start_xmit include/linux/netdevice.h:5011 [inline]
 xmit_one net/core/dev.c:3590 [inline]
 dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3606
 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434
 dev_queue_xmit include/linux/netdevice.h:3168 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236
 synproxy_send_client_synack+0x8a4/0xe20 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:5672 [inline]
 __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5785
 process_backlog+0x662/0x15b0 net/core/dev.c:6117
 __napi_poll+0xcb/0x490 net/core/dev.c:6883
 napi_poll net/core/dev.c:6952 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7074
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 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
 </TASK>