KCSAN: data-race in check_mmio_spte / kvm_set_memslot (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 418baf2c Linux 5.10-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1572d593500000
kernel config: https://syzkaller.appspot.com/x/.config?x=cf114765a0c30afa
dashboard link: https://syzkaller.appspot.com/bug?extid=1b79c9c4f558970278ed
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [k...@vger.kernel.org linux-...@vger.kernel.org pbon...@redhat.com]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1b79c9...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in check_mmio_spte / kvm_set_memslot

write to 0xffff88801be7d800 of 8 bytes by task 25233 on cpu 1:
install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1146 [inline]
kvm_set_memslot+0x945/0xa00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1222
__kvm_set_memory_region+0x708/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1374
kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1395 [inline]
kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1407 [inline]
kvm_vm_ioctl+0x822/0x17d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3708
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
__x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88801be7d800 of 8 bytes by task 25226 on cpu 0:
check_mmio_spte+0x58/0x160 arch/x86/kvm/mmu/mmu.c:254
handle_mmio_page_fault+0x64c/0x890 arch/x86/kvm/mmu/mmu.c:3579
kvm_mmu_page_fault+0x348/0x3c0 arch/x86/kvm/mmu/mmu.c:5053
handle_ept_misconfig+0x96/0x150 arch/x86/kvm/vmx/vmx.c:5375
vmx_handle_exit+0x2fd/0x7e0 arch/x86/kvm/vmx/vmx.c:6068
vcpu_enter_guest+0x1978/0x2390 arch/x86/kvm/x86.c:9025
vcpu_run+0x26e/0x730 arch/x86/kvm/x86.c:9090
kvm_arch_vcpu_ioctl_run+0x362/0x660 arch/x86/kvm/x86.c:9307
kvm_vcpu_ioctl+0x562/0x8f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3234
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
__x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25226 Comm: syz-executor.2 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.