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): P6204/1:b..l P6129/1:b..l P6210/3:b..l P6213/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=8781, q=1278069 ncpus=2)
task:syz.1.67        state:R  running task     stack:27672 pid:6213  tgid:6211  ppid:5826   task_flags:0x40044c flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109
 irqentry_exit+0x36/0x90 kernel/entry/common.c:307
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
RIP: 0010:unwind_next_frame+0xb8a/0x20a0 arch/x86/kernel/unwind_orc.c:585
Code: 00 00 4d 8d 7d 34 4c 89 ef 4c 89 44 24 28 48 89 4c 24 20 48 89 74 24 18 e8 73 f2 ff ff 84 c0 0f 84 fd f7 ff ff 48 8b 7c 24 18 <e8> 51 ea ff ff 48 89 ee 48 8b 4c 24 20 48 ba 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000c0f72c8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc9000c0f8000
RDX: ffffc9000c0f7f01 RSI: ffffc9000c0f7f20 RDI: ffffc9000c0f7f20
RBP: ffffc9000c0f7380 R08: ffffffff91433628 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000a58e R12: ffffc9000c0f7388
R13: ffffc9000c0f7338 R14: ffffc9000c0f7f28 R15: ffffc9000c0f736c
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204
 kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371
 fill_pool lib/debugobjects.c:403 [inline]
 debug_objects_fill_pool lib/debugobjects.c:725 [inline]
 debug_objects_fill_pool+0x228/0x500 lib/debugobjects.c:697
 debug_object_activate+0x10b/0x4c0 lib/debugobjects.c:814
 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
 __call_rcu_common.constprop.0+0x35/0xa10 kernel/rcu/tree.c:3079
 slab_free_hook mm/slub.c:2345 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x16d/0x4d0 mm/slub.c:4745
 exit_mmap+0x511/0xb90 mm/mmap.c:1309
 __mmput+0x12a/0x410 kernel/fork.c:1121
 mmput+0x62/0x70 kernel/fork.c:1144
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7c4/0x2bd0 kernel/exit.c:952
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1386d8e5ab
RSP: 002b:00007f1387bb7f10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f1386d8e5ab
RDX: 00007f1387bb8fe0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007f1387bb8fe0 R08: 0000000000000000 R09: 00312e6364755f79
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000200000000080 R15: 00007f1386e1c28d
 </TASK>
task:syz.4.68        state:R  running task     stack:26248 pid:6210  tgid:6210  ppid:5841   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6966
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xe2e/0x1680 mm/filemap.c:3757
 do_fault_around mm/memory.c:5548 [inline]
 do_read_fault mm/memory.c:5581 [inline]
 do_fault mm/memory.c:5724 [inline]
 do_pte_missing mm/memory.c:4251 [inline]
 handle_pte_fault mm/memory.c:6069 [inline]
 __handle_mm_fault+0x3b38/0x5490 mm/memory.c:6212
 handle_mm_fault+0x589/0xd10 mm/memory.c:6381
 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f604a66ec50
RSP: 002b:00007fff17705db0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f604b4e5720 RCX: 000000110c230000
RDX: 0000000000000aab RSI: ffffffffbfffffff RDI: 0000000000000001
RBP: ffffffff81824aab R08: 00007f604a9b6118 R09: 00007f604a9a2000
R10: 00007f60499fd008 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000000 R14: ffffffff818243c1 R15: 0000000000000000
 </TASK>
task:udevd           state:R  running task     stack:26568 pid:6129  tgid:6129  ppid:5202   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6966
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194
 sock_def_readable+0x15b/0x600 net/core/sock.c:3583
 unix_dgram_sendmsg+0xc9a/0x17a0 net/unix/af_unix.c:2236
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 sock_write_iter+0x4ff/0x5b0 net/socket.c:1131
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x6c4/0x1150 fs/read_write.c:686
 ksys_write+0x1f8/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c7fca7407
RSP: 002b:00007ffd501d4220 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9c80383880 RCX: 00007f9c7fca7407
RDX: 0000000000000000 RSI: 00007ffd501d42c7 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f9c803836e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:syz.0.66        state:R  running task     stack:26968 pid:6204  tgid:6203  ppid:5831   task_flags:0x40054c flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6966
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1765 [inline]
 zap_pmd_range mm/memory.c:1827 [inline]
 zap_pud_range mm/memory.c:1856 [inline]
 zap_p4d_range mm/memory.c:1877 [inline]
 unmap_page_range+0x106b/0x4350 mm/memory.c:1898
 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1941
 unmap_vmas+0x218/0x470 mm/memory.c:1985
 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284
 __mmput+0x12a/0x410 kernel/fork.c:1121
 mmput+0x62/0x70 kernel/fork.c:1144
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x7c4/0x2bd0 kernel/exit.c:952
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4bff58e9a9
RSP: 002b:00007f4c00424038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: fffffffffffffe00 RBX: 00007f4bff7b5fa0 RCX: 00007f4bff58e9a9
RDX: 0000000000000001 RSI: 0000200000000580 RDI: 0000000000000003
RBP: 00007f4bff610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000010048095 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4bff7b5fa0 R15: 00007ffe29f76208
 </TASK>
rcu: rcu_preempt kthread starved for 9855 jiffies! g8781 f0x2 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:27784 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 5c 0f f6 48 89 df e8 8e b0 0f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 f5 d2 ff f5 65 8b 05 8e d9 46 08 85 c0 74 16 5b
RSP: 0018:ffffc90000a07fa0 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff8880249fe610 RCX: ffffffff81c3b81f
RDX: 0000000000000000 RSI: ffffffff8de30036 RDI: ffffffff8c157460
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90a94057 R11: 0000000000000001 R12: 0000000000000001
R13: ffff8881764eca00 R14: ffff8880249fe660 R15: ffff888175236800
FS:  0000000000000000(0000) GS:ffff888124820000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556e29d5c8 CR3: 000000005dd9c000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 ref_tracker_alloc+0x2fe/0x5b0 lib/ref_tracker.c:214
 __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
 netdev_hold include/linux/netdevice.h:4370 [inline]
 dst_init+0xda/0x580 net/core/dst.c:52
 dst_alloc+0xbb/0x1a0 net/core/dst.c:93
 rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1642
 __mkroute_output net/ipv4/route.c:2643 [inline]
 ip_route_output_key_hash_rcu+0x87a/0x28f0 net/ipv4/route.c:2864
 ip_route_output_key_hash+0x137/0x2e0 net/ipv4/route.c:2694
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2921
 ip_route_output_key include/net/route.h:179 [inline]
 ip_route_me_harder+0x565/0x12f0 net/ipv4/netfilter.c:53
 synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431
 synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484
 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
 nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e6/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
 nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623
 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:272
 NF_HOOK include/linux/netfilter.h:315 [inline]
 ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:469 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:448 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 NF_HOOK include/linux/netfilter.h:311 [inline]
 ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:568
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5977
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090
 process_backlog+0x442/0x15e0 net/core/dev.c:6442
 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 6b 6d 02 e9 83 fb 02 00 0f 1f 00 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 43 89 23 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 00000000012b8a85 RBX: 0000000000000001 RCX: ffffffff8b868c99
RDX: 0000000000000000 RSI: ffffffff8de30036 RDI: ffffffff8c157460
RBP: ffffed1003c55488 R08: 0000000000000001 R09: ffffed10170a6645
R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801e2aa440 R14: ffffffff90a94050 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>