sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=135c/1/0x4000000000000000 softirq=79026/79026 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16553/1:b..l P5234/1:b..l rcu: (detected by 0, t=10502 jiffies, g=73305, q=272 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14932 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4877 [inline] RIP: 0010:__lock_acquire+0x99a/0xd20 kernel/locking/lockdep.c:5187 Code: 48 c7 c7 a1 8e c4 8d e8 24 1d 8a ff e8 af ab 95 ff e8 3a 87 03 00 e9 1d 03 00 00 83 bf 18 0b 00 00 00 41 0f 94 c4 41 80 f4 03 <44> 3b bf 28 0b 00 00 0f 8d 1e fc ff ff e9 15 fb ff ff ba 02 00 00 RSP: 0018:ffffc90000a08ad0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000000a421d RDX: 0000000000000002 RSI: 0000000000004000 RDI: ffff888033c68000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff84d5285a R10: ffffc90000a08cb0 R11: fffff52000141198 R12: ffffffffffffff02 R13: 0000000000000002 R14: ffff888033c68b80 R15: 0000000000000001 FS: 00007fd6abe80880(0000) GS:ffff888125ae7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000000c0 CR3: 000000002fad4000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline] debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:483 __run_hrtimer kernel/time/hrtimer.c:1745 [inline] __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217 Code: 24 65 48 8b 0c 25 08 90 c3 92 65 8b 15 f8 b6 03 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c <8b> 91 58 16 00 00 83 fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 48 RSP: 0018:ffffc9001b117908 EFLAGS: 00000246 RAX: ffffffff8b816a5c RBX: 000000000000000a RCX: ffff888033c68000 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 000000000000000a RBP: ffffffff8bfc8e67 R08: ffff888033c68000 R09: 0000000000000008 R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000005 R13: ffffffffffff0a00 R14: 0000000000000000 R15: 0000000000000018 widen_string+0x1c/0x2a0 lib/vsprintf.c:626 vsnprintf+0x739/0xf00 lib/vsprintf.c:2926 tomoyo_supervisor+0x133/0x1480 security/tomoyo/common.c:2170 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline] tomoyo_path_number_perm+0x438/0x5a0 security/tomoyo/file.c:734 security_file_ioctl+0xcb/0x2d0 security/security.c:2982 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd6ab71d378 Code: 00 00 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 07 89 d0 c3 0f 1f 40 00 48 8b 15 49 3a 0d RSP: 002b:00007fffffc6a0f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000055eaa970b050 RCX: 00007fd6ab71d378 RDX: 00007fffffc6a130 RSI: 0000000080280215 RDI: 0000000000000009 RBP: 0000000000000009 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000009 task:udevd state:R running task stack:21576 pid:5234 tgid:5234 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172 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+0xfd/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127 sock_def_readable+0x1fb/0x550 net/core/sock.c:3551 __netlink_sendskb net/netlink/af_netlink.c:1265 [inline] netlink_sendskb+0xa1/0x140 net/netlink/af_netlink.c:1271 netlink_unicast+0x397/0x9e0 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2617 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2671 __sys_sendmsg net/socket.c:2703 [inline] __do_sys_sendmsg net/socket.c:2708 [inline] __se_sys_sendmsg net/socket.c:2706 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2706 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd6ab6a7407 RSP: 002b:00007fffffc70610 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd6abe80880 RCX: 00007fd6ab6a7407 RDX: 0000000000000000 RSI: 00007fffffc70670 RDI: 0000000000000004 RBP: 000055eaa9723830 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b3 R13: 000055eaa96fd9e0 R14: 0000000000000000 R15: 0000000000000000 task:syz-executor state:R running task stack:20968 pid:16553 tgid:16553 ppid:16534 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172 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+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1329 [inline] copy_pmd_range+0x7630/0x7f00 mm/memory.c:1389 copy_pud_range mm/memory.c:1426 [inline] copy_p4d_range mm/memory.c:1450 [inline] copy_page_range+0xc14/0x1270 mm/memory.c:1538 dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834 dup_mm kernel/fork.c:1504 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1556 copy_process+0x1706/0x3c00 kernel/fork.c:2196 kernel_clone+0x21e/0x840 kernel/fork.c:2624 __do_sys_clone kernel/fork.c:2765 [inline] __se_sys_clone kernel/fork.c:2749 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2749 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd5f9d85493 RSP: 002b:00007ffecf54edf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd5f9d85493 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555555e1f7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000f335f R15: 00007ffecf54ef90 rcu: rcu_preempt kthread starved for 10490 jiffies! g73305 f0x0 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:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 0 UID: 0 PID: 17566 Comm: sed Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 36 79 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 e1 74 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 c5 74 RSP: 0018:ffffc900044df580 EFLAGS: 00000293 RAX: ffffffff81b4645b RBX: 1ffff110170e7ffd RCX: ffff888023c33c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900044df700 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce R10: dffffc0000000000 R11: fffffbfff1f872cf R12: ffff8880b873ffe8 R13: dffffc0000000000 R14: ffff8880b863b200 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881259e7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb7b907e9c CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x174/0xb40 mm/mmap.c:1266 __mmput+0x118/0x430 kernel/fork.c:1148 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb7ba666c5 Code: Unable to access opcode bytes at 0x7fbb7ba6669b. RSP: 002b:00007ffd3b275e98 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fbb7bb67fe8 RCX: 00007fbb7ba666c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbb7bb66680 R15: 00007fbb7bb68000