sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ab84/1/0x4000000000000000 softirq=136553/136554 fqs=1 rcu: (detected by 0, t=10506 jiffies, g=107249, q=540 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24669 Comm: sed Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline] RIP: 0010:trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1780 [inline] RIP: 0010:__hrtimer_run_queues+0x55b/0xc60 kernel/time/hrtimer.c:1841 Code: b6 44 1d 00 84 c0 0f 85 6e 03 00 00 41 c7 07 00 00 00 00 48 8b 5c 24 18 0f 1f 44 00 00 e8 5d 5b 12 00 65 44 8b 2d 79 a7 c0 10 07 00 00 00 44 89 ee e8 88 5f 12 00 41 83 fd 07 0f 87 98 01 00 RSP: 0018:ffffc90000a07400 EFLAGS: 00000006 RAX: ffffffff81ada8b3 RBX: ffff8880b8927d08 RCX: ffff88801c3a8000 RDX: 0000000000010100 RSI: ffffffff8d8f4f27 RDI: ffff88801c3a8000 RBP: ffffc90000a07558 R08: ffff8880754cf15f R09: 1ffff1100ea99e2b R10: dffffc0000000000 R11: ffffed100ea99e2c R12: ffff8880754cf340 R13: 0000000000000001 R14: 0000000000000001 R15: ffff88801c3a8b18 FS: 0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f994f9fb2c0 CR3: 000000003be5d000 CR4: 0000000000350ef0 Call Trace: hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__rcu_read_lock+0x32/0x60 kernel/rcu/tree_plugin.h:416 Code: 1c 25 08 50 6e 92 48 81 c3 84 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 <3d> 00 00 00 40 7d 07 5b e9 dc 37 69 ff cc 90 0f 0b 90 eb f3 89 d9 RSP: 0018:ffffc90000a07788 EFLAGS: 00000202 RAX: 0000000000000004 RBX: ffff88801c3a8484 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: ffffffff89b18781 RDI: ffffc90000a07868 RBP: dffffc0000000000 R08: ffffc90000a07930 R09: 0000000000000009 R10: dffffc0000000000 R11: ffffffff81ac2e60 R12: 1ffff92000140f0d R13: ffffc90000a078a0 R14: ffffc90000a07868 R15: ffffc90000a080f8 rcu_read_lock include/linux/rcupdate.h:865 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x9e/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 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:2543 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6752 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb+0x55/0x70 net/core/skbuff.c:1166 tcp_rcv_established+0x1493/0x2670 net/ipv4/tcp_input.c:6349 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1931 tcp_v4_rcv+0x2675/0x2f20 net/ipv4/tcp_ipv4.c:2374 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 dst_input include/net/dst.h:474 [inline] ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584 ip_list_rcv_finish net/ipv4/ip_input.c:636 [inline] ip_sublist_rcv+0x74c/0xa10 net/ipv4/ip_input.c:644 ip_list_rcv+0x3e2/0x430 net/ipv4/ip_input.c:678 __netif_receive_skb_list_ptype net/core/dev.c:6122 [inline] __netif_receive_skb_list_core+0x7d2/0x800 net/core/dev.c:6169 __netif_receive_skb_list net/core/dev.c:6221 [inline] netif_receive_skb_list_internal+0x96f/0xcb0 net/core/dev.c:6312 gro_normal_list include/net/gro.h:524 [inline] gro_flush_normal include/net/gro.h:532 [inline] napi_complete_done+0x2f2/0x7c0 net/core/dev.c:6681 virtqueue_napi_complete drivers/net/virtio_net.c:766 [inline] virtnet_poll+0x23cb/0x2db0 drivers/net/virtio_net.c:3134 __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+0x286/0x870 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 common_interrupt+0xbb/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x18/0x90 kernel/kcov.c:314 Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 14 25 08 50 6e 92 65 8b 0d c8 47 ae 10 <81> e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 7c 16 00 00 RSP: 0018:ffffc9000467f6f0 EFLAGS: 00000293 RAX: ffffffff823e71c8 RBX: ffff88805696e238 RCX: 0000000080000000 RDX: ffff88801c3a8000 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: 0000000000000000 R08: ffffc9000467faf7 R09: 1ffff920008cff5e R10: dffffc0000000000 R11: fffff520008cff5f R12: ffffffff8e09d2a0 R13: ffff88805696e23c R14: ffff88805696e260 R15: 1ffff1100ad2dc4c vfsuid_valid include/linux/mnt_idmapping.h:57 [inline] HAS_UNMAPPED_ID include/linux/fs.h:2587 [inline] atime_needs_update+0x108/0x6d0 fs/inode.c:2143 pick_link+0x41d/0xe80 fs/namei.c:1931 step_into+0xbc9/0xe80 fs/namei.c:2021 walk_component fs/namei.c:2157 [inline] link_path_walk+0x77b/0xea0 fs/namei.c:2519 path_lookupat+0x97/0x430 fs/namei.c:2675 filename_lookup+0x212/0x570 fs/namei.c:2705 vfs_statx+0xf8/0x550 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 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: 0033:0x7f9a0746deaa Code: b8 05 00 00 00 0f 05 48 3d 00 f0 ff ff 77 01 c3 f7 d8 89 05 08 44 01 00 b8 ff ff ff ff c3 66 90 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 f7 d8 89 05 e0 43 01 00 RSP: 002b:00007ffd7cde1588 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffd7cde1597 RCX: 00007f9a0746deaa RDX: 00007ffd7cde1640 RSI: 00007ffd7cde1590 RDI: 00000000ffffff9c RBP: 00007ffd7cde1700 R08: 00007ffd7cde1787 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001e R13: 00007f9a07442000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10500 jiffies! g107249 f0x0 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:27288 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+0x711/0x8a0 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: CPU: 0 UID: 0 PID: 5835 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:srso_alias_safe_ret+0x0/0x7 arch/x86/lib/retpoline.S:210 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0018:ffffc90004df7530 EFLAGS: 00000293 RAX: ffffffff81b4949b RBX: 1ffff11017127ffd RCX: ffff88802e825ac0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004df76c0 R08: ffffffff8f7ceb77 R09: 1ffffffff1ef9d6e R10: dffffc0000000000 R11: fffffbfff1ef9d6f R12: ffff8880b893ffe8 R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001 FS: 000055556c029500(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34017ff8 CR3: 000000005d2f2000 CR4: 0000000000350ef0 Call Trace: srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:220 csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471 dup_mmap+0x1594/0x1b10 mm/mmap.c:1873 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1706/0x3c00 kernel/fork.c:2181 kernel_clone+0x21e/0x840 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 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: 0033:0x7f2032585e13 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd3ccd5df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2032585e13 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556c0297d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000cb705 R15: 00007ffd3ccd5f90