syzbot


KCSAN: data-race in kvm_arch_vcpu_load / kvm_vcpu_kick

Status: auto-closed as invalid on 2020/10/21 04:02
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 743d, last: 743d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in kvm_arch_vcpu_load / kvm_vcpu_kick (4) 1 537d 513d 0/24 auto-closed as invalid on 2021/05/18 19:52
upstream KCSAN: data-race in kvm_arch_vcpu_load / kvm_vcpu_kick (2) 2 698d 701d 0/24 auto-closed as invalid on 2020/12/05 18:11
upstream KCSAN: data-race in kvm_arch_vcpu_load / kvm_vcpu_kick (3) 1 605d 605d 0/24 auto-closed as invalid on 2021/03/08 08:59

Sample crash report:
==================================================================
BUG: KCSAN: data-race in kvm_arch_vcpu_load / kvm_vcpu_kick

write to 0xffff8880b498c160 of 4 bytes by task 11381 on cpu 0:
 kvm_arch_vcpu_load+0x423/0x580 arch/x86/kvm/x86.c:3741
 vcpu_load+0x4e/0x80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:210
 kvm_arch_vcpu_ioctl_set_regs+0x16/0x30 arch/x86/kvm/x86.c:9014
 kvm_vcpu_ioctl+0x4ca/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3260
 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 0xffff8880b498c160 of 4 bytes by task 11375 on cpu 1:
 kvm_vcpu_kick+0x17/0x170 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2855
 kvm_arch_memslots_updated+0x85/0xc0 arch/x86/kvm/x86.c:10155
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1146 [inline]
 kvm_set_memslot+0x85e/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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11375 Comm: syz-executor.0 Not tainted 5.9.0-rc5-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 2020/09/16 03:53 upstream fc4f28bb3daf 18d7d030 .config log report info
* Struck through repros no longer work on HEAD.