rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6308/1:b..l rcu: (detected by 0, t=10502 jiffies, g=46361, q=713 ncpus=1) task:kworker/u8:9 state:R running task stack:0 pid:6308 tgid:6308 ppid:2 task_flags:0x4208060 flags:0x00000010 Workqueue: events_power_efficient gc_worker Call trace: __switch_to+0x2b4/0x6e4 arch/arm64/kernel/process.c:775 (T) context_switch kernel/sched/core.c:5533 [inline] __schedule+0x135c/0x2b00 kernel/sched/core.c:7284 preempt_schedule_irq+0x74/0x174 kernel/sched/core.c:7606 raw_irqentry_exit_cond_resched+0x30/0x40 kernel/entry/common.c:145 irqentry_exit_to_kernel_mode_preempt+0x44/0x54 include/linux/irq-entry-common.h:468 arm64_exit_to_kernel_mode_preempt+0x1c/0x38 arch/arm64/kernel/entry-common.c:107 __el1_irq arch/arm64/kernel/entry-common.c:571 [inline] el1_interrupt+0x4c/0x60 arch/arm64/kernel/entry-common.c:581 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:586 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:602 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P) arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) seqcount_lockdep_reader_access+0xe4/0x104 include/linux/seqlock.h:75 (P) nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:348 [inline] gc_worker+0x2a8/0x144c net/netfilter/nf_conntrack_core.c:1534 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 worker_thread+0x798/0xbd0 kernel/workqueue.c:3560 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 rcu: rcu_preempt kthread starved for 1381 jiffies! g46361 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00000010 Call trace: __switch_to+0x2b4/0x6e4 arch/arm64/kernel/process.c:775 (T) context_switch kernel/sched/core.c:5533 [inline] __schedule+0x135c/0x2b00 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x13c/0x20c kernel/sched/core.c:7376 schedule_timeout+0x13c/0x28c kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x260/0xde8 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x148/0x230 kernel/rcu/tree.c:2330 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 2854 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 Workqueue: bat_events batadv_tt_purge pstate: 03400005 (nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : in_softirq_really kernel/kcov.c:167 [inline] pc : check_kcov_mode+0x20/0x54 kernel/kcov.c:179 lr : __sanitizer_cov_trace_pc+0x28/0x5c kernel/kcov.c:213 sp : ffff80008f7e7200 x29: ffff80008f7e7200 x28: dfff800000000000 x27: ffff700011efce48 x26: 0000000000000028 x25: ffff0000b6451ea8 x24: 0000000000000000 x23: 0000000000000028 x22: ffff0000b514ad58 x21: 0000000000000014 x20: ffff0000c9451d80 x19: ffff8000850abc38 x18: ffff80011b876000 x17: ffff0001a4fd3e07 x16: 00000000004d3fa6 x15: 0000000000000001 x14: 00000000039b1dc5 x13: 0000000000000005 x12: 0000000000000000 x11: 0000000000000000 x10: ffff700011efce51 x9 : 0000000000000101 x8 : ffff0000c9451d80 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000000 x3 : ffff8000850abc08 x2 : 0000000000000000 x1 : ffff0000c9451d80 x0 : 0000000000000002 Call trace: preempt_count arch/arm64/include/asm/preempt.h:12 [inline] (P) in_softirq_really kernel/kcov.c:167 [inline] (P) check_kcov_mode+0x20/0x54 kernel/kcov.c:179 (P) synproxy_parse_options+0x154/0x6c8 net/netfilter/nf_synproxy_core.c:41 nft_synproxy_do_eval+0x28c/0x4dc net/netfilter/nft_synproxy.c:135 nft_synproxy_eval+0x34/0x48 net/netfilter/nft_synproxy.c:248 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x418/0x13c8 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x284/0x3d4 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc8/0x224 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x1f0/0x398 include/linux/netfilter.h:323 ip_local_deliver+0x128/0x188 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:481 [inline] ip_rcv_finish+0x20c/0x230 net/ipv4/ip_input.c:492 NF_HOOK+0x308/0x398 include/linux/netfilter.h:325 ip_rcv+0x7c/0x9c net/ipv4/ip_input.c:612 __netif_receive_skb_one_core+0xc8/0x110 net/core/dev.c:6297 __netif_receive_skb+0x34/0x128 net/core/dev.c:6410 process_backlog+0x588/0x14e0 net/core/dev.c:6761 __napi_poll+0xb4/0x328 net/core/dev.c:7830 napi_poll net/core/dev.c:7893 [inline] net_rx_action+0x5b0/0xc14 net/core/dev.c:8050 handle_softirqs+0x324/0xcbc kernel/softirq.c:645 __do_softirq+0x14/0x20 kernel/softirq.c:679 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:78 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:901 do_softirq_own_stack+0x1c/0x28 arch/arm64/kernel/irq.c:83 do_softirq+0x90/0xf8 kernel/softirq.c:546 __local_bh_enable_ip+0x190/0x234 kernel/softirq.c:473 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline] _raw_spin_unlock_bh+0x3c/0x4c kernel/locking/spinlock.c:245 spin_unlock_bh include/linux/spinlock.h:407 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2390 [inline] batadv_tt_purge+0x3e4/0x7b4 net/batman-adv/translation-table.c:3754 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 rescuer_thread+0x68c/0xd90 kernel/workqueue.c:3703 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854