rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10499 ticks this GP) idle=c81/1/0x4000000000000000 softirq=250982/250982 fqs=2843 (t=10502 jiffies g=414177 q=1758) rcu: rcu_preempt kthread starved for 4589 jiffies! g414177 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:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:553 NMI backtrace for cpu 1 CPU: 1 PID: 30180 Comm: syz-executor.4 Not tainted 5.16.0-rc5-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:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 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 5e ad 14 f8 48 89 ef e8 a6 23 15 f8 e8 c1 e3 35 f8 fb bf 01 00 00 00 f6 eb 07 f8 65 8b 05 ef 29 bb 76 85 c0 74 02 5d c3 e8 0b ff b8 RSP: 0018:ffffc900031ef2c0 EFLAGS: 00000206 RAX: 0000000001ce7b09 RBX: dffffc0000000000 RCX: 1ffffffff1fef8e6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff8bd55138 R08: 0000000000000001 R09: ffffffff8ff77a0f R10: 0000000000000001 R11: 0000000000000001 R12: 1ffffffff1701e30 R13: ffff88805db58180 R14: ffffffff8bd55138 R15: ffffc90003787b28 rwsem_down_write_slowpath+0x576/0x1110 kernel/locking/rwsem.c:1127 __down_write_common kernel/locking/rwsem.c:1268 [inline] __down_write_common kernel/locking/rwsem.c:1265 [inline] __down_write kernel/locking/rwsem.c:1277 [inline] down_write+0x135/0x150 kernel/locking/rwsem.c:1524 kernfs_activate+0x2a/0x1d0 fs/kernfs/dir.c:1293 kernfs_add_one+0x368/0x4c0 fs/kernfs/dir.c:766 __kernfs_create_file+0x29c/0x350 fs/kernfs/file.c:1014 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 device_add_groups drivers/base/core.c:2473 [inline] device_add_attrs drivers/base/core.c:2632 [inline] device_add+0x14ba/0x1ee0 drivers/base/core.c:3345 netdev_register_kobject+0x181/0x430 net/core/net-sysfs.c:2010 register_netdevice+0xd31/0x1500 net/core/dev.c:10336 register_netdev+0x2d/0x50 net/core/dev.c:10460 vti6_init_net+0x449/0x860 net/ipv6/ip6_vti.c:1162 ops_init+0xaf/0x470 net/core/net_namespace.c:140 setup_net+0x40f/0xa30 net/core/net_namespace.c:326 copy_net_ns+0x318/0x760 net/core/net_namespace.c:470 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x2da7/0x75a0 kernel/fork.c:2194 kernel_clone+0xe7/0xab0 kernel/fork.c:2582 __do_sys_clone+0xc8/0x110 kernel/fork.c:2699 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: 0033:0x7f047cdfce99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f047b772168 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f047cf0ff60 RCX: 00007f047cdfce99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: f70a86956630e51d RBP: 00007f047ce56ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd8e819e4f R14: 00007f047b772300 R15: 0000000000022000 ---------------- 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 5e ad 14 f8 callq 0xf814ad75 17: 48 89 ef mov %rbp,%rdi 1a: e8 a6 23 15 f8 callq 0xf81523c5 1f: e8 c1 e3 35 f8 callq 0xf835e3e5 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 f6 eb 07 f8 callq 0xf807ec25 <-- trapping instruction 2f: 65 8b 05 ef 29 bb 76 mov %gs:0x76bb29ef(%rip),%eax # 0x76bb2a25 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5d pop %rbp 3b: c3 retq 3c: e8 .byte 0xe8 3d: 0b ff or %edi,%edi 3f: b8 .byte 0xb8