| From c4e0e4ab4cf3ec2b3f0b628ead108d677644ebd9 Mon Sep 17 00:00:00 2001 |
| From: Jim Mattson <jmattson@google.com> |
| Date: Mon, 11 May 2020 15:56:16 -0700 |
| Subject: KVM: x86: Fix off-by-one error in kvm_vcpu_ioctl_x86_setup_mce |
| |
| From: Jim Mattson <jmattson@google.com> |
| |
| commit c4e0e4ab4cf3ec2b3f0b628ead108d677644ebd9 upstream. |
| |
| Bank_num is a one-based count of banks, not a zero-based index. It |
| overflows the allocated space only when strictly greater than |
| KVM_MAX_MCE_BANKS. |
| |
| Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup") |
| Signed-off-by: Jue Wang <juew@google.com> |
| Signed-off-by: Jim Mattson <jmattson@google.com> |
| Reviewed-by: Peter Shier <pshier@google.com> |
| Message-Id: <20200511225616.19557-1-jmattson@google.com> |
| Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/x86.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/x86/kvm/x86.c |
| +++ b/arch/x86/kvm/x86.c |
| @@ -3739,7 +3739,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce( |
| unsigned bank_num = mcg_cap & 0xff, bank; |
| |
| r = -EINVAL; |
| - if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) |
| + if (!bank_num || bank_num > KVM_MAX_MCE_BANKS) |
| goto out; |
| if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000)) |
| goto out; |
