From 53bbffd24f1273f03ec34e09040de24839ee93c7 Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Mon, 11 May 2020 15:56:16 -0700 Subject: KVM: x86: Fix off-by-one error in kvm_vcpu_ioctl_x86_setup_mce 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 Signed-off-by: Jim Mattson Reviewed-by: Peter Shier Message-Id: <20200511225616.19557-1-jmattson@google.com> Reviewed-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5f44827e4962..1477e23827c2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3214,7 +3214,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, 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; -- cgit v1.2.1