rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15833/1:b..l rcu: (detected by 1, t=10503 jiffies, g=125005, q=804 ncpus=2) task:syz-executor state:R running task stack:22928 pid:15833 tgid:15833 ppid:15814 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 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:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320 Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 93 6c 87 04 00 <74> 1d 83 3d 6a 9e 87 04 00 74 14 65 48 8b 0d 68 25 91 07 31 c0 83 RSP: 0018:ffffc90005237918 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffc900052379d8 RCX: ffffc90005237b08 RDX: ffffc90005237a01 RSI: dffffc0000000000 RDI: ffffc900052379d0 RBP: 1ffffffff2194f01 R08: ffffc90005237af0 R09: 0000000000000000 R10: ffffc90005237a18 R11: fffff52000a46f45 R12: ffffc90005230000 R13: ffffffff8176a21f R14: ffffc900052379c8 R15: ffffc90005237b00 rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1b5d/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5672 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] kmem_cache_alloc_noprof+0x2b8/0x650 mm/slub.c:4946 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 getname_flags fs/namei.c:230 [inline] getname include/linux/fs.h:2537 [inline] class_filename_constructor include/linux/fs.h:2564 [inline] __do_sys_unlink fs/namei.c:5615 [inline] __se_sys_unlink+0x1e/0x140 fs/namei.c:5613 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5267f9bf47 RSP: 002b:00007f526833ecb8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5267f9bf47 RDX: 00007f526833ece0 RSI: 00007f526833ed70 RDI: 00007f526833ed70 RBP: 00007f526833ed70 R08: 00007f526833fd70 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007f526833fe00 R13: 00007f52680321ca R14: 00000000000ac80d R15: 00007f526833fe40 rcu: rcu_preempt kthread starved for 451 jiffies! g125005 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:28408 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 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: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:skb_network_header include/linux/skbuff.h:3133 [inline] RIP: 0010:skb_network_offset include/linux/skbuff.h:3256 [inline] RIP: 0010:ipv6_find_hdr+0xb9/0x1110 net/ipv6/exthdrs_core.c:194 Code: f8 f2 49 89 44 1d 08 41 c7 44 1d 10 f8 f2 f8 f3 e8 5c f8 52 f7 4c 89 f1 49 8d be d0 00 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 <4c> 89 74 24 08 74 0a e8 ab 16 c0 f7 48 8b 4c 24 08 4c 8b b1 d0 00 RSP: 0018:ffffc90000a08680 EFLAGS: 00000246 RAX: 1ffff1104591855a RBX: dffffc0000000000 RCX: ffff88822c8c2a00 RDX: 0000000000000100 RSI: ffffc90000a08850 RDI: ffff88822c8c2ad0 RBP: ffffc90000a087f0 R08: ffffc90000a08840 R09: 0000000000000002 R10: 000000000000000a R11: 0000000000000100 R12: ffffc90000a08850 R13: 1ffff920001410e0 R14: ffff88822c8c2a00 R15: ffffc90000a08860 FS: 0000000000000000(0000) GS:ffff888125372000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557752da38 CR3: 000000000e746000 CR4: 00000000003526f0 Call Trace: nft_set_pktinfo_ipv6 include/net/netfilter/nf_tables_ipv6.h:15 [inline] nft_do_chain_inet+0x139/0x4b0 net/netfilter/nft_chain_filter.c:156 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x774/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 4c 7e 02 c3 cc cc cc cc 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 0f 00 2d 83 b7 1f 00 fb f4 7c 03 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e40 EFLAGS: 00000246 RAX: ffff888125372000 RBX: ffffffff819a5f8c RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8c292100 RDI: ffffffff819a5f8c RBP: ffffc90000197f10 R08: ffff8880b87338db R09: 1ffff110170e671b R10: dffffc0000000000 R11: ffffed10170e671c R12: 0000000000000000 R13: 1ffff11003bd0000 R14: 1ffff92000032fd0 R15: dffffc0000000000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x1cc/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157