rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=167537, q=118314 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 5163 (4295114329-4295109166), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 5164 jiffies! g167537 f0x2 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:25784 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3387 Comm: kworker/R-krdsd Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: krdsd rds_connect_worker RIP: 0010:__sanitizer_cov_trace_pc+0x5d/0x70 kernel/kcov.c:235 Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 RSP: 0018:ffffc90000006838 EFLAGS: 00000246 RAX: ffffffff899155bd RBX: 0000000000000000 RCX: ffff888031c31e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffffc90000006930 R08: ffffffff899155af R09: 1ffffffff2851d34 R10: dffffc0000000000 R11: ffffffff81400fd0 R12: 1ffff92000000d0c R13: ffff888211c2b780 R14: dffffc0000000000 R15: 1ffff110423856f4 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f63f368f314 CR3: 00000000644e4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:135 [inline] cpumask_check include/linux/cpumask.h:142 [inline] cpumask_test_cpu include/linux/cpumask.h:570 [inline] cpu_online include/linux/cpumask.h:1117 [inline] trace_netif_rx include/trace/events/net.h:158 [inline] netif_rx_internal+0xbd/0x630 net/core/dev.c:5212 __netif_rx+0x78/0xc0 net/core/dev.c:5253 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:3620 [inline] dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3636 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4466 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] ip6_finish_output2+0x1263/0x1780 net/ipv6/ip6_output.c:141 ip6_finish_output+0x41e/0x840 net/ipv6/ip6_output.c:226 synproxy_send_tcp_ipv6+0x568/0x7c0 net/netfilter/nf_synproxy_core.c:851 synproxy_send_client_synack_ipv6+0x827/0xcc0 net/netfilter/nf_synproxy_core.c:897 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:90 [inline] nft_synproxy_do_eval+0x739/0xa60 net/netfilter/nft_synproxy.c:145 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:5704 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5817 process_backlog+0x662/0x15b0 net/core/dev.c:6149 __napi_poll+0xcb/0x490 net/core/dev.c:6902 napi_poll net/core/dev.c:6971 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7093 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__srcu_check_read_flavor+0x68/0x150 kernel/rcu/srcutree.c:728 Code: 00 fc ff df 65 4c 8b 35 76 7c 7d 7e 48 83 c5 08 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 9c c5 7e 00 4c 8b 6d 00 <4b> 8d 5c 2e 20 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 8c RSP: 0018:ffffc9000cc17710 EFLAGS: 00000246 RAX: 1ffffffff1d49f44 RBX: ffff888042522640 RCX: 0000000000000000 RDX: 0000000000000cc0 RSI: 0000000000000001 RDI: ffffffff8ea4fa18 RBP: ffffffff8ea4fa20 R08: 00000000ffffffff R09: 1ffffffff203279e R10: dffffc0000000000 R11: fffffbfff203279f R12: dffffc0000000000 R13: 0000000000039040 R14: ffff8880b8600000 R15: 0000000000000001 srcu_check_read_flavor include/linux/srcutree.h:269 [inline] srcu_read_lock+0x12/0x60 include/linux/srcu.h:247 kasan_quarantine_reduce+0x51/0x170 mm/kasan/quarantine.c:259 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 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_noprof+0x1d9/0x380 mm/slub.c:4175 sk_prot_alloc+0x58/0x210 net/core/sock.c:2162 sk_alloc+0x38/0x370 net/core/sock.c:2221 inet_create+0x648/0xea0 net/ipv4/af_inet.c:326 __sock_create+0x4c0/0xa30 net/socket.c:1558 rds_tcp_conn_path_connect+0x2bb/0xbc0 rds_connect_worker+0x1dd/0x2a0 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 rescuer_thread+0x63f/0x10a0 kernel/workqueue.c:3494 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