sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5620/1:b..l rcu: (detected by 0, t=10503 jiffies, g=60529, q=2548 ncpus=2) task:kworker/0:3 state:R running task stack:24128 pid:5620 tgid:5620 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:seqcount_lockdep_reader_access+0xed/0x100 include/linux/seqlock.h:76 Code: 00 75 11 e8 85 f6 d7 f7 4d 85 f6 75 16 e8 7b f6 d7 f7 eb 15 e8 74 f6 d7 f7 e8 5f 39 e2 01 4d 85 f6 74 ea e8 65 f6 d7 f7 fb 5b <41> 5e c3 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 RSP: 0018:ffffc90003e3f990 EFLAGS: 00000293 RAX: ffffffff89ef0c2b RBX: 0000000000000001 RCX: ffff888035fa9f00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003e3faf0 R08: ffffffff90575b37 R09: 1ffffffff20aeb66 R10: dffffc0000000000 R11: fffffbfff20aeb67 R12: ffff88801e6cc618 R13: dffffc0000000000 R14: 0000000000000200 R15: 000000000000517c nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline] gc_worker+0x31b/0x1890 net/netfilter/nf_conntrack_core.c:1534 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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: rcu_preempt kthread starved for 3349 jiffies! g60529 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: krds_cp_wq#2/7 rds_connect_worker RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x4f4/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49 8d 1c 47 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 48 39 e8 4c 0f 46 f9 48 RSP: 0018:ffffc90000a08180 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff90d621a0 RCX: dffffc0000000000 RDX: ffffffff90d621a0 RSI: ffffffff9186de2a RDI: ffffffff8c4bba20 RBP: ffffffff8abc7ea8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffffffff90d621a0 R13: ffffffff90d621a0 R14: ffffc90000a08228 R15: ffffffff90d621a0 FS: 0000000000000000(0000) GS:ffff888125058000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe49211a000 CR3: 0000000079cf2000 CR4: 00000000003526f0 Call Trace: 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 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6504 vxcan_xmit+0x1f7/0x780 drivers/net/can/vxcan.c:62 __netdev_start_xmit include/linux/netdevice.h:5423 [inline] netdev_start_xmit include/linux/netdevice.h:5432 [inline] xmit_one net/core/dev.c:3918 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3934 __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4907 dev_queue_xmit include/linux/netdevice.h:3455 [inline] can_send+0x941/0xd30 net/can/af_can.c:279 can_can_gw_rcv+0xd09/0xfd0 net/can/gw.c:569 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0x126/0x7a0 net/can/af_can.c:602 can_receive+0x2c6/0x440 net/can/af_can.c:674 can_rcv+0x1f9/0x330 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6241 [inline] __netif_receive_skb net/core/dev.c:6354 [inline] process_backlog+0xbf0/0x1860 net/core/dev.c:6705 __napi_poll+0xaa/0x330 net/core/dev.c:7764 napi_poll net/core/dev.c:7827 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7984 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 __inet6_bind+0x386/0xf30 net/ipv6/af_inet6.c:419 kernel_bind+0x13e/0x1c0 net/socket.c:3646 rds_tcp_conn_path_connect+0x53b/0x920 net/rds/tcp_connect.c:175 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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