KCSAN: data-race in handle_mmio_page_fault / kvm_set

KCSAN: data-race in handle_mmio_page_fault / kvm_set_memslot
Status: auto-closed as invalid on 2020/11/08 13:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 397d, last: 385d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in handle_mmio_page_fault / kvm_set_memslot (3)	2	254d	289d	0/22	auto-closed as invalid on 2021/03/19 14:24
upstream	KCSAN: data-race in handle_mmio_page_fault / kvm_set_memslot (2)	1	330d	321d	0/22	auto-closed as invalid on 2021/01/02 05:15
upstream	KCSAN: data-race in handle_mmio_page_fault / kvm_set_memslot (4)	1	215d	215d	0/22	auto-closed as invalid on 2021/04/27 19:30

Sample crash report:

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

write to 0xffff888070cd9800 of 8 bytes by task 657 on cpu 0:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1148 [inline]
 kvm_set_memslot+0x866/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1224
 __kvm_set_memory_region+0x708/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1370
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1391 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1403 [inline]
 kvm_vm_ioctl+0x81d/0x17c0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3704
 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 0xffff888070cd9800 of 8 bytes by task 655 on cpu 1:
 mmio_info_in_cache arch/x86/kvm/mmu/mmu.c:3904 [inline]
 handle_mmio_page_fault+0xa7/0x860 arch/x86/kvm/mmu/mmu.c:3969
 kvm_mmu_page_fault+0x369/0x410 arch/x86/kvm/mmu/mmu.c:5445
 handle_ept_misconfig+0x99/0x230 arch/x86/kvm/vmx/vmx.c:5361
 vmx_handle_exit+0x558/0xc30 arch/x86/kvm/vmx/vmx.c:6125
 vcpu_enter_guest+0x1ada/0x2660 arch/x86/kvm/x86.c:8655
 vcpu_run+0x26e/0x740 arch/x86/kvm/x86.c:8720
 kvm_arch_vcpu_ioctl_run+0x38d/0x6a0 arch/x86/kvm/x86.c:8937
 kvm_vcpu_ioctl+0x565/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3230
 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: 655 Comm: syz-executor.3 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info
ci2-upstream-kcsan-gce	2020/10/04 13:08	upstream	22fbc037cd32	5ef9c291	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/03 04:12	upstream	d3d45f8220d6	2653fa43	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/22 07:53	upstream	98477740630f	9e1fa68e	.config	log	report	info