rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=502/1/0x4000000000000000 softirq=140936/140937 fqs=50 (t=10500 jiffies g=233837 q=633) rcu: rcu_preempt kthread starved for 10399 jiffies! g233837 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: rcu_preempt R running task 28912 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x7d3/0xc40 kernel/sched/core.c:4178 NMI backtrace for cpu 0 CPU: 0 PID: 16684 Comm: syz-executor.3 Not tainted 5.8.0-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:77 [inline] dump_stack+0x1f0/0x31e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x199/0x2a0 kernel/rcu/tree_stall.h:320 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline] check_cpu_stall kernel/rcu/tree_stall.h:627 [inline] rcu_pending kernel/rcu/tree.c:3489 [inline] rcu_sched_clock_irq+0x1928/0x1eb0 kernel/rcu/tree.c:2504 update_process_times+0x12c/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:176 [inline] tick_sched_timer+0x254/0x410 kernel/time/tick-sched.c:1320 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x112/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x57/0x80 kernel/locking/spinlock.c:199 Code: 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 00 c8 4b 89 e8 ea 7c 93 f9 48 83 3d 52 a8 2b 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 3f 7a 30 f9 65 8b 05 44 de e1 77 85 c0 74 02 5b RSP: 0018:ffffc90000007e10 EFLAGS: 00000282 RAX: 1ffffffff1297900 RBX: ffff8880ae825400 RCX: dffffc0000000000 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffffffff88201f7f RBP: ffffc90000007f00 R08: ffffffff817a2fd0 R09: ffffed1015d04a81 R10: ffffed1015d04a81 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8882019f4860 R14: ffff8882019f4868 R15: ffffffff86849210 expire_timers kernel/time/timer.c:1448 [inline] __run_timers+0x726/0x930 kernel/time/timer.c:1773 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1786 __do_softirq+0x268/0x80c kernel/softirq.c:292 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0xe0/0x1a0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:387 [inline] __irq_exit_rcu+0x1e1/0x1f0 kernel/softirq.c:417 irq_exit_rcu+0x6/0x50 kernel/softirq.c:429 sysvec_apic_timer_interrupt+0x117/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587 RIP: 0010:stack_trace_consume_entry+0x4d/0x270 kernel/stacktrace.c:86 Code: c1 ef 03 41 8a 04 17 84 c0 0f 85 ed 00 00 00 44 8b 43 10 48 8d 6b 08 49 89 ec 49 c1 ec 03 41 8a 04 14 84 c0 0f 85 02 01 00 00 <44> 3b 45 00 0f 83 38 01 00 00 48 8d 7b 0c 49 89 fd 49 c1 ed 03 41 RSP: 0018:ffffc900017ff828 EFLAGS: 00000246 RAX: ffffffff83645300 RBX: ffffc900017ff918 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffffff836453ea RDI: ffffc900017ff918 RBP: ffffc900017ff920 R08: 0000000000000002 R09: ffffc900017ff928 R10: fffff520002fff1b R11: 0000000000000000 R12: 1ffff920002fff24 R13: ffffffff8163bf60 R14: ffffc900017ff918 R15: 1ffff920002fff25 arch_stack_walk+0xa8/0xe0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xad/0x150 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x24b/0x330 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:669 [inline] tomoyo_encode2+0x25a/0x560 security/tomoyo/realpath.c:45 tomoyo_encode security/tomoyo/realpath.c:80 [inline] tomoyo_realpath_from_path+0x5d6/0x630 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x18f/0x690 security/tomoyo/file.c:723 security_file_ioctl+0x55/0xb0 security/security.c:1480 ksys_ioctl fs/ioctl.c:747 [inline] __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl+0x48/0x160 fs/ioctl.c:760 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cba9 Code: Bad RIP value. RSP: 002b:00007fb452277c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f4f40 RCX: 000000000045cba9 RDX: 0000000020000300 RSI: 00000000000089a1 RDI: 0000000000000007 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000006c9 R14: 00000000004c9c0b R15: 00007fb4522786d4