KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to

KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa
Status: auto-closed as invalid on 2020/07/25 12:23
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 485d, last: 485d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (2)	1	442d	442d	0/22	auto-closed as invalid on 2020/09/06 22:08
upstream	KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (4)	1	259d	259d	0/22	auto-closed as invalid on 2021/03/08 13:59
upstream	KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (3)	2	344d	315d	0/22	auto-closed as invalid on 2020/12/21 11:51

Sample crash report:

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

write to 0xffff888121d29000 of 8 bytes by task 12278 on cpu 0:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1092 [inline]
 kvm_set_memslot+0x866/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1168
 __kvm_set_memory_region+0x708/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1314
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1335 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1347 [inline]
 kvm_vm_ioctl+0x81d/0x17c0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3639
 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+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888121d29000 of 8 bytes by task 12329 on cpu 1:
 vcpu_match_mmio_gen arch/x86/kvm/x86.h:189 [inline]
 vcpu_match_mmio_gpa arch/x86/kvm/x86.h:217 [inline]
 vcpu_is_mmio_gpa arch/x86/kvm/x86.c:5680 [inline]
 vcpu_mmio_gva_to_gpa+0x2c4/0x5a0 arch/x86/kvm/x86.c:5714
 emulator_read_write_onepage+0xe7/0x490 arch/x86/kvm/x86.c:5825
 emulator_read_write+0x170/0x300 arch/x86/kvm/x86.c:5885
 emulator_read_emulated+0x37/0x40 arch/x86/kvm/x86.c:5912
 read_emulated arch/x86/kvm/emulate.c:1457 [inline]
 segmented_read arch/x86/kvm/emulate.c:1481 [inline]
 x86_emulate_insn+0x39b/0x2c60 arch/x86/kvm/emulate.c:5625
 x86_emulate_instruction+0x70d/0x2ae0 arch/x86/kvm/x86.c:6968
 kvm_mmu_page_fault+0x336/0x410 arch/x86/kvm/mmu/mmu.c:5471
 handle_ept_violation+0x232/0x5c0 arch/x86/kvm/vmx/vmx.c:5314
 vmx_handle_exit+0x554/0xb40 arch/x86/kvm/vmx/vmx.c:6093
 vcpu_enter_guest+0x189c/0x23e0 arch/x86/kvm/x86.c:8593
 vcpu_run+0x26e/0x750 arch/x86/kvm/x86.c:8658
 kvm_arch_vcpu_ioctl_run+0x38d/0x690 arch/x86/kvm/x86.c:8879
 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+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12329 Comm: syz-executor.1 Not tainted 5.8.0-rc1-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	2020/06/20 12:21	upstream	672f9255a727	c655ec77	.config	log	report