rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=3db/1/0x4000000000000000 softirq=15886/15886 fqs=453 (t=10502 jiffies g=21573 q=162) rcu: rcu_preempt kthread starved for 9597 jiffies! g21573 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:27504 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4f00 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:359 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:551 NMI backtrace for cpu 0 CPU: 0 PID: 6707 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 ae 0b 0d f8 48 89 ef e8 66 81 0d f8 e8 d1 66 2e f8 fb bf 01 00 00 00 06 3c 00 f8 65 8b 05 8f 0f b3 76 85 c0 74 02 5d c3 e8 fb e4 b0 RSP: 0018:ffffc90003af7500 EFLAGS: 00000202 RAX: 0000000002e69aef RBX: dffffc0000000000 RCX: 1ffffffff1ffa4ee RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8881400914f0 R08: 0000000000000001 R09: ffffffff8ffcda4f R10: 0000000000000001 R11: 0000000000000001 R12: 1ffffffff1701e30 R13: ffff88802ab4a080 R14: ffff8881400914f0 R15: ffffc90002c276e0 rwsem_down_write_slowpath+0x576/0x1110 kernel/locking/rwsem.c:1118 __down_write_common kernel/locking/rwsem.c:1259 [inline] __down_write_common kernel/locking/rwsem.c:1256 [inline] __down_write kernel/locking/rwsem.c:1268 [inline] down_write+0x135/0x150 kernel/locking/rwsem.c:1515 kernfs_add_one+0xa4/0x550 fs/kernfs/dir.c:726 __kernfs_create_file+0x29c/0x350 fs/kernfs/file.c:1016 sysfs_add_file_mode_ns+0x20f/0x3f0 fs/sysfs/file.c:294 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x322/0xb10 fs/sysfs/group.c:148 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:188 internal_create_groups fs/sysfs/group.c:184 [inline] sysfs_create_groups+0x25/0x50 fs/sysfs/group.c:214 create_dir lib/kobject.c:100 [inline] kobject_add_internal+0x583/0xa60 lib/kobject.c:255 kobject_add_varg lib/kobject.c:390 [inline] kobject_init_and_add+0x101/0x160 lib/kobject.c:473 ext4_register_sysfs+0xb5/0x360 fs/ext4/sysfs.c:526 __ext4_fill_super fs/ext4/super.c:5397 [inline] ext4_fill_super+0xaaa0/0xe800 fs/ext4/super.c:5557 get_tree_bdev+0x440/0x760 fs/super.c:1295 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:2994 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount fs/namespace.c:3522 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc1a601b51a Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc1a498ef88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fc1a601b51a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fc1a498efe0 RBP: 00007fc1a498f020 R08: 00007fc1a498f020 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000 R13: 0000000020000100 R14: 00007fc1a498efe0 R15: 00000000200000c0 ---------------- Code disassembly (best guess): 0: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 5: 55 push %rbp 6: 48 8b 74 24 08 mov 0x8(%rsp),%rsi b: 48 89 fd mov %rdi,%rbp e: 48 83 c7 18 add $0x18,%rdi 12: e8 ae 0b 0d f8 callq 0xf80d0bc5 17: 48 89 ef mov %rbp,%rdi 1a: e8 66 81 0d f8 callq 0xf80d8185 1f: e8 d1 66 2e f8 callq 0xf82e66f5 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 06 3c 00 f8 callq 0xf8003c35 <-- trapping instruction 2f: 65 8b 05 8f 0f b3 76 mov %gs:0x76b30f8f(%rip),%eax # 0x76b30fc5 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5d pop %rbp 3b: c3 retq 3c: e8 .byte 0xe8 3d: fb sti 3e: e4 b0 in $0xb0,%al