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): P2/1:b..l P5493/1:b..l rcu: (detected by 0, t=10502 jiffies, g=157769, q=838 ncpus=2) task:dhcpcd state:R running task stack:22792 pid:5493 tgid:5493 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x44/0x3e0 kernel/locking/lockdep.c:5879 Code: 8b 05 80 ec f3 10 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 83 ec f3 10 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 ac 1b 01 0e <73> 16 e8 a5 ea 08 00 84 c0 75 0d f6 05 d9 26 eb 0d 01 0f 84 ad 02 RSP: 0018:ffffc90003526e50 EFLAGS: 00000297 RAX: 0000000000000001 RBX: ffffffff90bc8001 RCX: 2673a87fed23b500 RDX: ffffc90003526f01 RSI: ffffffff81731db5 RDI: ffffffff8e13d320 RBP: dffffc0000000000 R08: ffffc90003527970 R09: 0000000000000000 R10: ffffc90003526fd8 R11: fffff520006a4dfd R12: ffffc90003527980 R13: ffffffff81731db5 R14: ffffffff8e13d320 R15: ffffffff81731db5 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3301 [inline] __put_partials+0x146/0x170 mm/slub.c:3848 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3923 __slab_free+0x2b9/0x390 mm/slub.c:5882 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_node_track_caller_noprof+0x519/0x800 mm/slub.c:5712 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2965 unix_dgram_sendmsg+0x461/0x1850 net/unix/af_unix.c:2153 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 do_iter_readv_writev+0x620/0x8c0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffb6eaea407 RSP: 002b:00007ffcf2802360 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007ffb6ea60740 RCX: 00007ffb6eaea407 RDX: 0000000000000005 RSI: 00007ffcf28023c0 RDI: 000000000000000a RBP: 0000561f5ef24870 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000561f8931cb80 R13: 000000000000012c R14: 0000000000004801 R15: 0000561f89317444 task:kthreadd state:R running task stack:25512 pid:2 tgid:2 ppid:0 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b fc f3 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900000771d8 EFLAGS: 00000206 RAX: 31c1860676dcdb00 RBX: 0000000000000000 RCX: 31c1860676dcdb00 RDX: 0000000000000000 RSI: ffffffff8d9d13e7 RDI: ffffffff8bc074e0 RBP: ffffffff81731db5 R08: 0000000000000000 R09: ffffffff81731db5 R10: ffffc90000077398 R11: ffffffff81abbcd0 R12: 0000000000000002 R13: ffffffff8e13d320 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3301 [inline] __put_partials+0x146/0x170 mm/slub.c:3848 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3923 __slab_free+0x2b9/0x390 mm/slub.c:5882 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_noprof+0x3c3/0x7f0 mm/slub.c:5615 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] lsm_blob_alloc security/security.c:690 [inline] lsm_task_alloc security/security.c:777 [inline] security_task_alloc+0x4d/0x360 security/security.c:3229 copy_process+0x1530/0x3c00 kernel/fork.c:2163 kernel_clone+0x21e/0x840 kernel/fork.c:2609 kernel_thread+0x10d/0x160 kernel/fork.c:2670 create_kthread kernel/kthread.c:486 [inline] kthreadd+0x575/0x770 kernel/kthread.c:846 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10420 jiffies! g157769 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__asan_memset+0x5/0x50 mm/kasan/shadow.c:83 Code: 01 00 00 00 e9 bc e4 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 RSP: 0018:ffffc90000a07c48 EFLAGS: 00000246 RAX: 1ffff92000140fac RBX: ffffc90000a07d60 RCX: 1ffff92000140f01 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000a07d78 RBP: dffffc0000000000 R08: 0000000000000003 R09: ffffffff81731db5 R10: ffffc90000a07d78 R11: ffffffff81abbcd0 R12: ffffc90000a08750 R13: ffffc90000a07d78 R14: ffffc90000a07d28 R15: ffffc90000a07d70 FS: 0000000000000000(0000) GS:ffff888125e12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000015c030 CR3: 000000007789c000 CR4: 00000000003526f0 Call Trace: unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 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:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2514 [inline] slab_free mm/slub.c:6566 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6676 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1398 nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145 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:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6079 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6192 process_backlog+0x60e/0x14f0 net/core/dev.c:6544 __napi_poll+0xc7/0x360 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: c3 e6 02 00 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 e3 f0 1c 00 f3 0f 1e fa fb f4 98 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: b3d3b1169af97f00 RBX: ffffffff81960ca7 RCX: b3d3b1169af97f00 RDX: 0000000000000001 RSI: ffffffff8d7e858c RDI: ffffffff8bc074e0 RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e0f70 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100385ab58 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147