sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=30002 jiffies, g=278801, q=94 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 30002 (4295523060-4295493058), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 30002 jiffies! g278801 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:0 pid:17 tgid:17 ppid:2 flags:0x00000008 Call trace: __switch_to+0xf4/0x168 arch/arm64/kernel/process.c:606 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x330/0x8f8 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x34/0x104 kernel/sched/core.c:6782 schedule_timeout+0x80/0xf4 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x138/0x48c kernel/rcu/tree.c:2045 rcu_gp_kthread+0x130/0x15c kernel/rcu/tree.c:2247 kthread+0x114/0x118 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G B 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Tainted: [B]=BAD_PAGE Hardware name: linux,dummy-virt (DT) pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : in_irqentry_text kernel/stacktrace.c:381 [inline] pc : filter_irq_stacks+0x38/0x74 kernel/stacktrace.c:397 lr : stack_depot_save_flags+0x2c/0x5c4 lib/stackdepot.c:609 sp : ffff800080003250 x29: ffff800080003250 x28: 000000000100007f x27: fbf000000304fa00 x26: 0000000000000001 x25: ffff800082720000 x24: 0000000000000000 x23: fcf000000911b000 x22: 0000000000000001 x21: 0000000000000820 x20: ffff8000800032f0 x19: 0000000000000003 x18: 0000000000000001 x17: f9f0000007234070 x16: ffff800080000000 x15: faf00000290a4840 x14: 0000000000000004 x13: 0000000000000021 x12: 0000000000004788 x11: faf00000290a4b10 x10: faf00000290a4810 x9 : 0000000000000000 x8 : 0000000000000029 x7 : ffff8000800104f0 x6 : ffff8000800104f0 x5 : ffff800080010000 x4 : ffff800080010510 x3 : ffff800081575fe4 x2 : 0000000000000005 x1 : 0000000000000029 x0 : ffff8000800032f0 Call trace: in_irqentry_text kernel/stacktrace.c:379 [inline] filter_irq_stacks+0x38/0x74 kernel/stacktrace.c:397 kasan_save_stack+0x50/0x64 mm/kasan/common.c:48 save_stack_info+0x40/0x158 mm/kasan/tags.c:106 kasan_save_alloc_info+0x14/0x20 mm/kasan/tags.c:142 unpoison_slab_object mm/kasan/common.c:319 [inline] unpoison_slab_object mm/kasan/common.c:308 [inline] __kasan_slab_alloc+0x94/0xcc mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x10c/0x2c4 mm/slub.c:4141 skb_clone+0x60/0xc4 net/core/skbuff.c:2084 netem_enqueue+0x554/0xa90 net/sched/sch_netem.c:485 dev_qdisc_enqueue net/core/dev.c:3787 [inline] __dev_xmit_skb net/core/dev.c:3883 [inline] __dev_queue_xmit+0x3dc/0xf24 net/core/dev.c:4394 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0x3c0/0x65c net/ipv4/ip_output.c:236 __ip_finish_output net/ipv4/ip_output.c:314 [inline] __ip_finish_output+0xa4/0x1a0 net/ipv4/ip_output.c:296 ip_finish_output+0x34/0x10c net/ipv4/ip_output.c:324 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip_output+0x68/0x100 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:450 [inline] ip_local_out+0x48/0x5c net/ipv4/ip_output.c:130 synproxy_send_tcp.isra.0+0x108/0x180 net/netfilter/nf_synproxy_core.c:439 synproxy_send_client_synack+0x1b0/0x200 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0x268/0x270 net/netfilter/nft_synproxy.c:141 nft_synproxy_eval+0x14/0x38 net/netfilter/nft_synproxy.c:247 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x108/0x484 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0xa0/0x114 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0x48/0x118 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0xec/0x120 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish+0x90/0xb0 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0xec/0xf8 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x58/0x84 net/core/dev.c:5666 __netif_receive_skb+0x18/0x60 net/core/dev.c:5779 process_backlog+0x84/0x13c net/core/dev.c:6111 __napi_poll+0x38/0x198 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x344/0x3c8 net/core/dev.c:6966 handle_softirqs+0x108/0x240 kernel/softirq.c:554 __do_softirq+0x14/0x20 kernel/softirq.c:588 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:81 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:889 do_softirq_own_stack+0x1c/0x28 arch/arm64/kernel/irq.c:86 invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0x8c/0xc4 kernel/softirq.c:649 __el1_irq arch/arm64/kernel/entry-common.c:537 [inline] el1_interrupt+0x38/0x64 arch/arm64/kernel/entry-common.c:551 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:556 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:594 __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] ksoftirqd_run_end kernel/softirq.c:411 [inline] run_ksoftirqd kernel/softirq.c:928 [inline] run_ksoftirqd+0x40/0x4c kernel/softirq.c:919 smpboot_thread_fn+0x208/0x22c kernel/smpboot.c:164 kthread+0x114/0x118 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860