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): P11/2:b..l P4180/1:b..l rcu: (detected by 0, t=30002 jiffies, g=20881, q=1367817 ncpus=2) task:udevd state:R running task stack:0 pid:4180 tgid:4180 ppid:3092 flags:0x00000004 Call trace: __switch_to+0xf4/0x190 arch/arm64/kernel/process.c:701 (T) context_switch kernel/sched/core.c:5369 [inline] __schedule+0x330/0x900 kernel/sched/core.c:6756 preempt_schedule_irq+0x3c/0x78 kernel/sched/core.c:7078 arm64_preempt_schedule_irq arch/arm64/kernel/entry-common.c:301 [inline] __el1_irq arch/arm64/kernel/entry-common.c:563 [inline] el1_interrupt+0x4c/0x64 arch/arm64/kernel/entry-common.c:575 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:580 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:596 __lookup_mnt+0x50/0x60 fs/namespace.c:807 (P) lookup_mnt+0x3c/0xac fs/namespace.c:837 (L) __traverse_mounts+0x128/0x1e4 fs/namei.c:1480 traverse_mounts fs/namei.c:1527 [inline] handle_mounts fs/namei.c:1630 [inline] step_into+0x198/0x654 fs/namei.c:1950 walk_component+0x4c/0x190 fs/namei.c:2118 link_path_walk.part.0.constprop.0+0x238/0x3bc fs/namei.c:2477 link_path_walk fs/namei.c:2407 [inline] path_lookupat+0x40/0x19c fs/namei.c:2633 filename_lookup+0xb8/0x1bc fs/namei.c:2663 user_path_at+0x48/0x70 fs/namei.c:3070 inotify_find_inode fs/notify/inotify/inotify_user.c:377 [inline] __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:771 [inline] __se_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:729 [inline] __arm64_sys_inotify_add_watch+0xb0/0x414 fs/notify/inotify/inotify_user.c:729 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151 el0_svc+0x30/0xe0 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:600 task:kworker/u8:0 state:R running task stack:0 pid:11 tgid:11 ppid:2 flags:0x00000008 Workqueue: events_power_efficient gc_worker Call trace: __switch_to+0xf4/0x190 arch/arm64/kernel/process.c:701 (T) context_switch kernel/sched/core.c:5369 [inline] __schedule+0x330/0x900 kernel/sched/core.c:6756 preempt_schedule_common kernel/sched/core.c:6935 [inline] preempt_schedule+0x48/0x60 kernel/sched/core.c:6959 __local_bh_enable_ip+0x68/0x98 kernel/softirq.c:389 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x20/0x2c kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] nf_nat_cleanup_conntrack+0x60/0x70 net/netfilter/nf_nat_core.c:1014 nf_conntrack_free+0xbc/0xcc net/netfilter/nf_conntrack_core.c:1730 nf_ct_destroy+0x68/0xec net/netfilter/nf_conntrack_core.c:598 nf_ct_put include/net/netfilter/nf_conntrack.h:186 [inline] nf_ct_put include/net/netfilter/nf_conntrack.h:183 [inline] nf_ct_gc_expired.part.0+0x8c/0xd4 net/netfilter/nf_conntrack_core.c:726 nf_ct_gc_expired net/netfilter/nf_conntrack_core.c:1569 [inline] gc_worker+0x2a4/0x540 net/netfilter/nf_conntrack_core.c:1568 process_one_work+0x15c/0x29c kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x24c/0x354 kernel/workqueue.c:3391 kthread+0x114/0x118 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 rcu: rcu_preempt kthread starved for 30002 jiffies! g20881 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:0 pid:17 tgid:17 ppid:2 flags:0x00000008 Call trace: __switch_to+0xf4/0x190 arch/arm64/kernel/process.c:701 (T) context_switch kernel/sched/core.c:5369 [inline] __schedule+0x330/0x900 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x34/0x104 kernel/sched/core.c:6848 schedule_timeout+0x80/0xf8 kernel/time/sleep_timeout.c:99 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:862 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 6.12.0-syzkaller-11677-g2ba9f676d0a2 #0 Hardware name: linux,dummy-virt (DT) pstate: 01400009 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : ipt_do_table+0x358/0x6a0 net/ipv4/netfilter/ip_tables.c:359 lr : local_bh_enable include/linux/bottom_half.h:33 [inline] lr : ipt_do_table+0x358/0x6a0 net/ipv4/netfilter/ip_tables.c:357 sp : ffff800082bfb890 x29: ffff800082bfb8b0 x28: f0f00000062bb120 x27: f5f0000008f8d900 x26: f0f0000008fe48d8 x25: 0000000000000001 x24: ffff800082790250 x23: 0000000001b2a1b9 x22: f0f0000008fe4948 x21: 0000000000000001 x20: ffff800081f425f0 x19: f5f000001dbc9f00 x18: 0000000000000001 x17: fbf000000a1eba30 x16: 000000000000001d x15: f0f0000008fe4840 x14: 0000000000000001 x13: 0000000000000021 x12: 0000000000004788 x11: f0f0000008fe4948 x10: f0f0000008fe4804 x9 : 0000000000001554 x8 : 0000000000000098 x7 : 0000000000000100 x6 : 0000000000000000 x5 : 0000000000000000 x4 : fff07ffffd17d000 x3 : 0000000001b2a1ba x2 : fbf00000032536c0 x1 : 0000000000000100 x0 : 0000000000000100 Call trace: local_bh_enable include/linux/bottom_half.h:33 [inline] (P) ipt_do_table+0x358/0x6a0 net/ipv4/netfilter/ip_tables.c:357 (P) local_bh_enable include/linux/bottom_half.h:33 [inline] (L) ipt_do_table+0x358/0x6a0 net/ipv4/netfilter/ip_tables.c:357 (L) iptable_mangle_hook+0x20/0x110 net/ipv4/netfilter/iptable_mangle.c:80 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:447 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:567 __netif_receive_skb_one_core+0x58/0x84 net/core/dev.c:5672 __netif_receive_skb+0x18/0x60 net/core/dev.c:5785 process_backlog+0x84/0x13c net/core/dev.c:6117 __napi_poll+0x38/0x198 net/core/dev.c:6877 napi_poll net/core/dev.c:6946 [inline] net_rx_action+0x344/0x3c8 net/core/dev.c:7068 handle_softirqs+0x108/0x240 kernel/softirq.c:554 run_ksoftirqd kernel/softirq.c:943 [inline] run_ksoftirqd+0x3c/0x4c kernel/softirq.c:935 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:862