rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=62761, q=939143 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 2063 (4295073265-4295071202), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 2064 jiffies! g62761 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:26040 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline] RIP: 0010:unwind_next_frame+0x214/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: ef 08 8b 15 be 35 25 0c 8d 42 ff 44 39 f8 0f 86 65 18 00 00 44 89 f8 4c 8d 2c 85 54 3f b8 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d RSP: 0018:ffffc900001573b8 EFLAGS: 00000213 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 460d20bfc8eb8900 RDX: 00000000000a59db RSI: ffffffff8bc1d1c0 RDI: ffffffff8bc1d180 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8171a9f5 R12: ffffffff82170840 R13: ffffffff90bc9b74 R14: ffffc90000157488 R15: 0000000000011708 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x100/0x570 lib/debugobjects.c:403 debug_objects_fill_pool lib/debugobjects.c:725 [inline] debug_object_assert_init+0x2b1/0x380 lib/debugobjects.c:1003 debug_timer_assert_init kernel/time/timer.c:845 [inline] debug_assert_init kernel/time/timer.c:890 [inline] __try_to_del_timer_sync+0x29/0x3a0 kernel/time/timer.c:1499 __timer_delete_sync+0x1fe/0x2d0 kernel/time/timer.c:1662 schedule_timeout+0x133/0x270 kernel/time/sleep_timeout.c:100 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3393 Comm: kworker/R-bat_e Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:memset+0xf/0x20 arch/x86/lib/memset_64.S:38 Code: 44 88 1f e9 4e f4 b9 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 e9 22 f4 b9 f5 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000006e38 EFLAGS: 00000202 RAX: ffffc90000006e00 RBX: ffff8881833b1780 RCX: 000000000000003b RDX: 000000000000003c RSI: 0000000000000000 RDI: ffffc90000006ea1 RBP: ffffc90000006f50 R08: 0000000000000003 R09: ffffc90000006ea0 R10: dffffc0000000000 R11: fffff52000000ddb R12: ffffc90000006ea0 R13: 0000000000000002 R14: ffff88805dd20000 R15: 1ffff92000000dd0 FS: 0000000000000000(0000) GS:ffff8881260cb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1961340990 CR3: 000000003275c000 CR4: 0000000000350ef0 Call Trace: __xfrm_decode_session+0xac/0xb80 net/xfrm/xfrm_policy.c:3504 xfrm_decode_session include/net/xfrm.h:1333 [inline] ip_route_me_harder+0x91c/0xfe0 net/ipv4/netfilter.c:66 synproxy_send_tcp+0x359/0x6c0 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8bb/0xe20 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:312 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5887 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6000 process_backlog+0x60e/0x14f0 net/core/dev.c:6352 __napi_poll+0xc7/0x480 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0x6ea/0xdf0 net/core/dev.c:7510 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x4d1/0x9e0 net/batman-adv/translation-table.c:3510 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3496 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245