syzbot


KCSAN: data-race in check_mmio_spte / kvm_set_memslot (4)

Status: auto-closed as invalid on 2021/02/26 09:27
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 574d, last: 574d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in check_mmio_spte / kvm_set_memslot (3) 3 634d 620d 0/23 auto-closed as invalid on 2020/12/28 17:11
upstream KCSAN: data-race in check_mmio_spte / kvm_set_memslot 2 739d 754d 0/23 auto-closed as invalid on 2020/09/14 12:48
upstream KCSAN: data-race in check_mmio_spte / kvm_set_memslot (2) 2 691d 699d 0/23 auto-closed as invalid on 2020/11/01 14:13

Sample crash report:
==================================================================
BUG: KCSAN: data-race in check_mmio_spte / kvm_set_memslot

write to 0xffff88810d9a5000 of 8 bytes by task 14291 on cpu 0:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1148 [inline]
 kvm_set_memslot+0x945/0xa00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1224
 __kvm_set_memory_region+0x794/0x930 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1376
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1397 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1409 [inline]
 kvm_vm_ioctl+0xacb/0x1c30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3824
 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 0xffff88810d9a5000 of 8 bytes by task 14273 on cpu 1:
 check_mmio_spte+0x58/0x170 arch/x86/kvm/mmu/mmu.c:254
 handle_mmio_page_fault+0x575/0x8d0 arch/x86/kvm/mmu/mmu.c:3594
 kvm_mmu_page_fault+0x348/0x3c0 arch/x86/kvm/mmu/mmu.c:5068
 handle_ept_misconfig+0x96/0x150 arch/x86/kvm/vmx/vmx.c:5355
 vmx_handle_exit+0x2fd/0x7e0 arch/x86/kvm/vmx/vmx.c:6048
 vcpu_enter_guest+0x1a26/0x2530 arch/x86/kvm/x86.c:9081
 vcpu_run+0x24e/0x680 arch/x86/kvm/x86.c:9147
 kvm_arch_vcpu_ioctl_run+0x443/0x820 arch/x86/kvm/x86.c:9374
 kvm_vcpu_ioctl+0x562/0x8f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3282
 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: 1 PID: 14273 Comm: syz-executor.3 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/01/22 09:27 upstream 83d09ad4b950 d4f4eca5 .config log report info KCSAN: data-race in check_mmio_spte / kvm_set_memslot