sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=10245, q=1286185 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 7887 (4294957743-4294949856), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 7888 jiffies! g10245 f0x2 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:25456 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x186c/0x4be0 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 32 Comm: kworker/R-write Not tainted 6.13.0-syzkaller-07644-gc2da8b3f914f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:__alloc_skb+0x2f4/0x440 net/core/skbuff.c:710 Code: df be 04 00 00 00 e8 4b e2 71 f8 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 22 01 00 00 c7 03 01 00 00 00 48 8b 44 24 20 <48> c7 44 24 40 0e 36 e0 45 49 c7 44 05 00 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90000006ec0 EFLAGS: 00000246 RAX: 1ffff92000000de0 RBX: 0000000000000000 RCX: ffff88801da95a00 RDX: 0000000000000100 RSI: 0000000000000004 RDI: ffff888028fffae0 RBP: ffffc90000006f90 R08: ffff888028fffae3 R09: 1ffff110051fff5c R10: dffffc0000000000 R11: ffffed10051fff5d R12: 1ffff1100b394a87 R13: dffffc0000000000 R14: ffff888059ca53c0 R15: ffff888059ca543e FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6f995fe000 CR3: 000000006e930000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: alloc_skb include/linux/skbuff.h:1331 [inline] synproxy_send_client_synack+0x1b9/0xe20 net/netfilter/nf_synproxy_core.c:460 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 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+0x4ad/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+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5828 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5941 process_backlog+0x662/0x15b0 net/core/dev.c:6289 __napi_poll+0xcb/0x490 net/core/dev.c:7106 napi_poll net/core/dev.c:7175 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7297 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 4e 90 2e f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 f3 1c 96 f5 65 8b 05 e4 44 0c 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90000a863a0 EFLAGS: 00000206 RAX: 5a3b72ec2b01bf00 RBX: 1ffff92000150c78 RCX: ffffffff819b575a RDX: dffffc0000000000 RSI: ffffffff8c0a9200 RDI: 0000000000000001 RBP: ffffc90000a86428 R08: ffffffff942f9877 R09: 1ffffffff285f30e R10: dffffc0000000000 R11: fffffbfff285f30f R12: dffffc0000000000 R13: 1ffff92000150c74 R14: ffffc90000a863c0 R15: 0000000000000246 __slab_free+0x26b/0x380 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_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4298 [inline] __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] kmalloc_array_noprof include/linux/slab.h:946 [inline] ext4_find_extent+0x22a/0xd50 fs/ext4/extents.c:916 ext4_ext_map_blocks+0x2e4/0x7d30 fs/ext4/extents.c:4205 ext4_map_create_blocks fs/ext4/inode.c:516 [inline] ext4_map_blocks+0x8bf/0x1990 fs/ext4/inode.c:702 mpage_map_one_extent fs/ext4/inode.c:2219 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2272 [inline] ext4_do_writepages+0x21c7/0x3df0 fs/ext4/inode.c:2735 ext4_writepages+0x213/0x3c0 fs/ext4/inode.c:2824 do_writepages+0x35f/0x880 mm/page-writeback.c:2708 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 writeback_inodes_wb+0x1ce/0x280 fs/fs-writeback.c:2077 wb_workfn+0x1047/0x1080 fs/fs-writeback.c:2352 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 rescuer_thread+0x63f/0x10a0 kernel/workqueue.c:3494 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244