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): P15676/1:b..l rcu: (detected by 0, t=10503 jiffies, g=102065, q=747249 ncpus=2) task:syz.1.1923 state:R running task stack:25872 pid:15676 tgid:15674 ppid:12428 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6674 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6996 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:stack_trace_save+0x77/0x1d0 kernel/stacktrace.c:114 Code: 41 48 c7 44 24 28 18 97 09 8e 48 c7 44 24 30 60 65 80 81 4c 8d 7c 24 20 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 00 00 f3 4b 89 04 2f <43> c7 44 2f 08 f3 f3 f3 f3 48 8d 7c 24 50 48 89 f8 48 c1 e8 03 42 RSP: 0018:ffffc90010a4f3e0 EFLAGS: 00000212 RAX: f3000000f1f1f1f1 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000010 RDI: ffffc90010a4f500 RBP: ffffc90010a4f4b0 R08: ffffffff82090312 R09: ffffc90010a4f500 R10: dffffc0000000000 R11: fffff52002149eb0 R12: ffffc90010a4f500 R13: dffffc0000000000 R14: ffffc90010a4f420 R15: 1ffff92002149e80 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 alloc_buffer_head+0x2a/0x290 fs/buffer.c:3020 folio_alloc_buffers+0x2bc/0x660 fs/buffer.c:928 grow_dev_folio fs/buffer.c:1068 [inline] grow_buffers fs/buffer.c:1109 [inline] __getblk_slow fs/buffer.c:1135 [inline] bdev_getblk+0x2a6/0x550 fs/buffer.c:1437 __bread_gfp+0x86/0x400 fs/buffer.c:1491 sb_bread include/linux/buffer_head.h:346 [inline] exfat_verify_boot_region fs/exfat/super.c:538 [inline] __exfat_fill_super fs/exfat/super.c:585 [inline] exfat_fill_super+0xe76/0x2a40 fs/exfat/super.c:641 get_tree_bdev+0x3f9/0x570 fs/super.c:1635 vfs_get_tree+0x92/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2c077f69a RSP: 002b:00007ff2c15a0e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff2c15a0ef0 RCX: 00007ff2c077f69a RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 00007ff2c15a0eb0 RBP: 00000000200000c0 R08: 00007ff2c15a0ef0 R09: 0000000000000800 R10: 0000000000000800 R11: 0000000000000246 R12: 0000000020000000 R13: 00007ff2c15a0eb0 R14: 0000000000001534 R15: 0000000020000ac0 rcu: rcu_preempt kthread starved for 1576 jiffies! g102065 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:24464 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6674 __schedule_loop kernel/sched/core.c:6751 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6766 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 24 Comm: ksoftirqd/1 Not tainted 6.11.0-syzkaller-09959-gabf2050f51fd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:stack_trace_consume_entry+0x4/0x280 kernel/stacktrace.c:83 Code: 6a ff ff ff e8 9d fc 42 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 fb 48 ba 00 00 00 RSP: 0018:ffffc900001e6a18 EFLAGS: 00000286 RAX: ffffffff81806678 RBX: ffffc900001e6a20 RCX: ffffffff917af000 RDX: ffffffff9195c401 RSI: ffffffff81806678 RDI: ffffc900001e6b00 RBP: ffffc900001e6ab0 R08: ffffc900001e6ab0 R09: ffffc900001e6a70 R10: dffffc0000000000 R11: ffffffff81806740 R12: ffff88801d680000 R13: ffffffff81806740 R14: ffffc900001e6b00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f18286656c0 CR3: 000000006fe5c000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x110/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x1a0/0x440 mm/slub.c:4728 skb_kfree_head net/core/skbuff.c:1086 [inline] skb_free_head net/core/skbuff.c:1098 [inline] skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1436 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4af/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 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+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcd/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244