GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=d9a4/1/0x4000000000000000 softirq=21426/21429 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=19085, q=384 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7225 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller-00248-g03d38806a902 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] RIP: 0010:lock_is_held_type+0x11c/0x190 kernel/locking/lockdep.c:5925 Code: 00 00 00 48 c7 c7 00 b7 2a 8c e8 7f 1a 00 00 b8 ff ff ff ff 65 0f c1 05 62 28 fa 73 83 f8 01 75 44 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb RSP: 0018:ffffc90000a18c20 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88802bb75a00 RDX: ffff88802bb75a00 RSI: ffffffff8c2ab700 RDI: ffffffff8c80f060 RBP: 0000000000000001 R08: ffffffff8a047f8b R09: fffff5200014317c R10: dffffc0000000000 R11: fffff5200014317c R12: 0000000000000046 R13: ffff88802bb75a00 R14: 00000000ffffffff R15: ffff88807aaad300 FS: 000055556ae15500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30118ff8 CR3: 000000006da42000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0xcd/0xca0 net/sched/sch_taprio.c:925 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59d/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5855 Code: 2b 00 74 08 4c 89 f7 e8 7a 45 8c 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000424fa80 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000849f5c RCX: ffff88802bb764e8 RDX: dffffc0000000000 RSI: ffffffff8c2ab700 RDI: ffffffff8c80f060 RBP: ffffc9000424fbc8 R08: ffffffff94549887 R09: 1ffffffff28a9310 R10: dffffc0000000000 R11: fffffbfff28a9311 R12: 1ffff92000849f58 R13: dffffc0000000000 R14: ffffc9000424fae0 R15: 0000000000000246 srcu_lock_acquire include/linux/srcu.h:164 [inline] srcu_read_lock include/linux/srcu.h:256 [inline] tomoyo_read_lock security/tomoyo/common.h:1108 [inline] tomoyo_path_number_perm+0x22d/0x770 security/tomoyo/file.c:722 security_file_ioctl+0xc6/0x2a0 security/security.c:2913 __do_sys_ioctl fs/ioctl.c:900 [inline] __se_sys_ioctl+0x46/0x170 fs/ioctl.c:892 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: 0033:0x7f8f4df8cd6b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fff48799c00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f8f4df8cd6b RDX: 00007fff48799c60 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007fff48799c60 R08: 000000000000000a R09: 0000000000000004 R10: 0000000000000009 R11: 0000000000000246 R12: 00007fff48799cec R13: 00007f8f4e00f378 R14: 00007f8f4ecd4620 R15: 00007f8f4e00f378 rcu: rcu_preempt kthread starved for 10506 jiffies! g19085 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:26104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 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+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/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: 5201 Comm: udevd Not tainted 6.14.0-rc4-syzkaller-00248-g03d38806a902 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bae/0x2d30 kernel/smp.c:885 Code: 89 e6 83 e6 01 31 ff e8 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 03 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 bb f0 0b RSP: 0018:ffffc90003c9f400 EFLAGS: 00000293 RAX: dffffc0000000000 RBX: 1ffff110170e88f9 RCX: ffff88807bcfbc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003c9f600 R08: ffffffff81b5ce30 R09: 1ffffffff28a930e R10: dffffc0000000000 R11: fffffbfff28a930f R12: ffff8880b863fb48 R13: ffff8880b87447c8 R14: ffff8880b863fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feb80da7bac CR3: 00000000582c8000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu+0x1aa/0x680 mm/mmu_gather.c:395 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488 exit_mmap+0x52a/0xd40 mm/mmap.c:1297 __mmput+0x115/0x420 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5395f16b6a Code: Unable to access opcode bytes at 0x7f5395f16b40. RSP: 002b:00007fffa13c5b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000010 RBX: 0000556a9e6f2040 RCX: 00007f5395f16b6a RDX: 0000000000000110 RSI: 00007fffa13c5d48 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000009463ba3 R09: 7fffffffffffffff R10: 00007f539633b038 R11: 0000000000000246 R12: 00007fffa13c5d48 R13: 0000556aa3870040 R14: 0000000000000000 R15: 0000000000000000