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): P5815/1:b..l P49/1:b..l P5827/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15461, q=405 ncpus=2) task:syz-executor state:R running task stack:23368 pid:5827 tgid:5827 ppid:5822 task_flags:0x400140 flags:0x00004002 Call Trace: 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_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:218 [inline] RIP: 0010:unwind_next_frame+0x256/0x20a0 arch/x86/kernel/unwind_orc.c:494 Code: 24 20 44 8b 5c 24 18 8d 50 01 8b 0c 8d 28 88 fb 91 48 b8 00 00 00 00 00 fc ff df 48 8d 3c 95 28 88 fb 91 49 89 f8 49 c1 e8 03 <45> 0f b6 04 00 48 89 f8 83 e0 07 83 c0 03 44 38 c0 7c 2e 45 84 c0 RSP: 0018:ffffc90002ee7960 EFLAGS: 00000a06 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000003 RDX: 0000000000000002 RSI: 00000000000a90ed RDI: ffffffff91fb8830 RBP: ffffc90002ee7a18 R08: 1ffffffff23f7106 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90002ee7a20 R13: ffffc90002ee79d0 R14: ffffc90002ee7a05 R15: ffffffff8100012f arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 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 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:322 user_path_at+0x24/0x60 fs/namei.c:3126 ksys_umount fs/namespace.c:2115 [inline] __do_sys_umount fs/namespace.c:2123 [inline] __se_sys_umount fs/namespace.c:2121 [inline] __x64_sys_umount+0x10a/0x1a0 fs/namespace.c:2121 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: 0033:0x7fcbdc58fcd7 RSP: 002b:00007fff17715408 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fcbdc610b55 RCX: 00007fcbdc58fcd7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff177154c0 RBP: 00007fff177154c0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff17716550 R13: 00007fcbdc610b55 R14: 000000000002e0e2 R15: 00007fff17716590 task:kworker/u8:3 state:R running task stack:24216 pid:49 tgid:49 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: 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_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:869 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1155 [inline] RIP: 0010:unwind_next_frame+0x3d9/0x20a0 arch/x86/kernel/unwind_orc.c:479 Code: b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 10 15 00 00 41 c7 45 00 00 00 00 00 31 ed 22 27 22 0a 85 c0 0f 85 a7 06 00 00 48 c7 c7 00 4e 5c 8e 48 8d RSP: 0018:ffffc90000ba6e38 EFLAGS: 00000297 RAX: ffffc90000ba8001 RBX: ffffc90000ba7978 RCX: ffffc90000ba8001 RDX: ffffc90000ba7980 RSI: ffffc90000ba7948 RDI: ffffc90000ba6eb8 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000009fe78 R12: ffffc90000ba6ef8 R13: ffffc90000ba6ea8 R14: ffffc90000ba7978 R15: ffffc90000ba6edc 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 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] cfg80211_inform_single_bss_data+0x53e/0x1df0 net/wireless/scan.c:2339 cfg80211_inform_bss_data+0x224/0x3bc0 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x26f/0x750 net/wireless/scan.c:3313 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0x1905/0x2fd0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1670 [inline] ieee80211_iface_work+0xbf4/0x1020 net/mac80211/iface.c:1724 cfg80211_wiphy_work+0x3dc/0x550 net/wireless/core.c:435 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 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:syz-executor state:R running task stack:23704 pid:5815 tgid:5815 ppid:5814 task_flags:0x400100 flags:0x00004002 Call Trace: 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_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline] RIP: 0010:__orc_find+0x65/0xf0 arch/x86/kernel/unwind_orc.c:102 Code: eb 0c 48 8d 6b 04 49 89 df 49 39 ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 <48> 89 da 48 c1 ea 03 0f b6 34 0a 48 89 da 83 e2 07 83 c2 03 40 38 RSP: 0018:ffffc90002f07860 EFLAGS: 00000246 RAX: ffffffff91f3fb3c RBX: ffffffff91335098 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff91335098 RBP: ffffffff91335098 R08: ffffffff91f3fb42 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000a8cb1 R12: ffffffff91335098 R13: ffffffff8b8cb10c R14: ffffffff91335098 R15: ffffffff91335098 orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x2ec/0x20a0 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 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 lsm_file_alloc security/security.c:733 [inline] security_file_alloc+0x34/0x2b0 security/security.c:2888 init_file+0x93/0x4c0 fs/file_table.c:159 alloc_empty_file+0x73/0x1e0 fs/file_table.c:241 alloc_file fs/file_table.c:354 [inline] alloc_file_pseudo+0x13a/0x230 fs/file_table.c:383 create_pipe_files+0x364/0x9a0 fs/pipe.c:942 __do_pipe_flags fs/pipe.c:988 [inline] do_pipe2+0xaf/0x1c0 fs/pipe.c:1036 __do_sys_pipe2 fs/pipe.c:1054 [inline] __se_sys_pipe2 fs/pipe.c:1052 [inline] __x64_sys_pipe2+0x54/0x80 fs/pipe.c:1052 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: 0033:0x7f4618b8d6c9 RSP: 002b:00007fff1a49da38 EFLAGS: 00000246 ORIG_RAX: 0000000000000125 RAX: ffffffffffffffda RBX: 000055558a9cfdc0 RCX: 00007f4618b8d6c9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 00007fff1a49da58 RBP: 00007fff1a49de00 R08: 0000000000000007 R09: 000055558a9d1540 R10: 974abc7f19503867 R11: 0000000000000246 R12: 000055558a9ccad0 R13: 000055558a9d15a8 R14: 00007fff1a49db80 R15: 000055558a9cd028 rcu: rcu_preempt kthread starved for 10628 jiffies! g15461 f0x0 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:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: 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 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: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-00857-gced1b9e0392d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 3b 67 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 f9 1c 00 fb f4 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: 000000000096b403 RBX: 0000000000000001 RCX: ffffffff8b8d1c99 RDX: 0000000000000000 RSI: ffffffff8de35f2f RDI: ffffffff8c15bf60 RBP: ffffed1003cd6488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e6b2440 R14: ffffffff90a96150 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881247f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff17714c58 CR3: 0000000061880000 CR4: 00000000003526f0 Call Trace: 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