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): P8988/1:b..l rcu: (detected by 1, t=10503 jiffies, g=34249, q=542210 ncpus=2) task:syz.0.889 state:R running task stack:22960 pid:8988 tgid:8986 ppid:5619 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xb3b/0x2550 arch/x86/kernel/unwind_orc.c:614 Code: 04 00 00 83 fe 03 0f 84 f1 01 00 00 83 fe 02 0f 85 a2 07 00 00 48 89 5c 24 48 49 8d 7e 08 48 89 fb 48 c1 eb 03 42 80 3c 23 00 <74> 09 e8 8e 0e bd 00 4c 8b 04 24 4d 8b 7e 08 49 8d 7e 10 49 89 fc RSP: 0018:ffffc9000312e6e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92000625cf2 RCX: ffffffff90c1e794 RDX: ffffffff91686746 RSI: 0000000000000002 RDI: ffffc9000312e790 RBP: 1ffffffff22d0ce8 R08: ffffc9000312ee60 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: ffffffff91686742 R14: ffffc9000312e788 R15: 1ffff92000625cf1 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] __kmalloc_cache_noprof+0x2ab/0x660 mm/slub.c:5485 _kmalloc_noprof include/linux/slab.h:988 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] ib_uverbs_add_one+0xca/0x700 drivers/infiniband/core/uverbs_main.c:1161 add_client_context+0x37c/0x7b0 drivers/infiniband/core/device.c:732 enable_device_and_get+0x19c/0x3e0 drivers/infiniband/core/device.c:1341 ib_register_device+0x10af/0x1380 drivers/infiniband/core/device.c:1468 siw_device_register drivers/infiniband/sw/siw/siw_main.c:71 [inline] siw_newlink+0x8fe/0xde0 drivers/infiniband/sw/siw/siw_main.c:430 nldev_newlink+0x5bc/0x650 drivers/infiniband/core/nldev.c:1816 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline] rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6ef/0xa40 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8c6a19e0d9 RSP: 002b:00007f8c6b133028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8c6a425fa0 RCX: 00007f8c6a19e0d9 RDX: 0000000024000090 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f8c6a235024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8c6a426038 R14: 00007f8c6a425fa0 R15: 00007fff84e0e2f8 rcu: rcu_preempt kthread starved for 1611 jiffies! g34249 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 1 UID: 0 PID: 5620 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:xfrm_fill_dst net/xfrm/xfrm_policy.c:2642 [inline] RIP: 0010:xfrm_bundle_create net/xfrm/xfrm_policy.c:2782 [inline] RIP: 0010:xfrm_resolve_and_create_bundle+0x297a/0x3070 net/xfrm/xfrm_policy.c:2875 Code: 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 fd 14 cb f7 48 8b 1b 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 20 02 00 00 <0f> b7 3b e8 4e f6 fe ff 48 85 c0 0f 84 a5 05 00 00 48 89 c3 48 83 RSP: 0018:ffffc90000a07c20 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88807f149a00 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000a07fb0 R08: ffffffff8a7cb3ad R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: ffff888051a2d584 R14: ffff8880363f7800 R15: ffff8880363f7800 FS: 000055558f0cf500(0000) GS:ffff888125058000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558f0cf4e8 CR3: 0000000022714000 CR4: 00000000003526f0 Call Trace: xfrm_bundle_lookup net/xfrm/xfrm_policy.c:3100 [inline] xfrm_lookup_with_ifid+0x576/0x1b40 net/xfrm/xfrm_policy.c:3231 icmpv6_route_lookup+0x203/0x610 net/ipv6/icmp.c:381 icmp6_send+0x114c/0x1b50 net/ipv6/icmp.c:793 icmpv6_send include/linux/icmpv6.h:24 [inline] nf_send_unreach6+0x59d/0xb60 net/ipv6/netfilter/nf_reject_ipv6.c:446 nft_reject_inet_eval+0x441/0x690 net/netfilter/nft_reject_inet.c:44 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6212 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0x774/0x1860 net/core/dev.c:6676 __napi_poll+0xaa/0x330 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7955 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0x11df/0x2550 arch/x86/kernel/unwind_orc.c:670 Code: 89 3b 43 0f b6 44 25 00 84 c0 0f 85 29 11 00 00 49 8d 46 36 c6 00 00 49 8d 5e 50 4c 8b 6c 24 18 48 8b 44 24 30 42 0f b6 04 20 <84> c0 4c 8b 04 24 0f 85 46 0e 00 00 42 0f b6 44 25 00 84 c0 0f 85 RSP: 0018:ffffc90003a6f448 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90003a6f598 RCX: 0000000000000000 RDX: ffffffff90ed5324 RSI: 0000000000000000 RDI: ffffc90003a6f5a8 RBP: 1ffffffff21daa64 R08: ffffc90003a6f5a7 R09: 0000000000000000 R10: ffffc90003a6f598 R11: fffff5200074deb5 R12: dffffc0000000000 R13: ffffffff90ed5320 R14: ffffc90003a6f548 R15: ffffc90003a6f590 __unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931 alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262 path_openat+0x8f/0x3830 fs/namei.c:4849 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f065879d3fc Code: 4c 89 54 24 18 41 89 f2 41 83 e2 40 75 40 89 f0 f7 d0 a9 00 00 41 00 74 35 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 44 48 8b 54 24 18 64 48 2b 14 25 28 00 00 00 RSP: 002b:00007ffd3e93aca0 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0658834474 RCX: 00007f065879d3fc RDX: 0000000000090800 RSI: 00007ffd3e93be50 RDI: 00000000ffffff9c RBP: 00007ffd3e93be3c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffd3e93be50 R13: 00007f0658834474 R14: 0000000000030a7c R15: 00007ffd3e93be90