syzbot

==================================================================
BUG: KCSAN: data-race in mm_update_next_owner / vcpu_enter_guest

write to 0xffff8880af8430a4 of 4 bytes by task 24755 on cpu 1:
 guest_exit_irqoff include/linux/context_tracking.h:163 [inline]
 vcpu_enter_guest+0x1afe/0x2760 arch/x86/kvm/x86.c:8571
 vcpu_run+0x27e/0x790 arch/x86/kvm/x86.c:8664
 kvm_arch_vcpu_ioctl_run+0x38d/0x6a0 arch/x86/kvm/x86.c:8885
 kvm_vcpu_ioctl+0x565/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3166
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl fs/ioctl.c:753 [inline]
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl+0xc9/0x130 fs/ioctl.c:760
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:760
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880af8430a4 of 4 bytes by task 5965 on cpu 0:
 mm_update_next_owner+0x1d9/0x4a0 kernel/exit.c:386
 exit_mm+0x2c0/0x330 kernel/exit.c:481
 do_exit+0x415/0x16e0 kernel/exit.c:792
 do_group_exit+0x17a/0x180 kernel/exit.c:903
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:914
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:912
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:912
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5965 Comm: syz-executor.4 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================