From adfb5d2746bfbe692324bd26a6de05a3a036b38e Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 19 Aug 2014 17:04:39 +0800 Subject: [PATCH] KVM: x86: fix check legal type of Variable Range MTRRs The first entry in each pair(IA32_MTRR_PHYSBASEn) defines the base address and memory type for the range; the second entry(IA32_MTRR_PHYSMASKn) contains a mask used to determine the address range. The legal values for the type field of IA32_MTRR_PHYSBASEn are 0,1,4,5, and 6. However, IA32_MTRR_PHYSMASKn don't have type field. This patch avoid check if the type field is legal for IA32_MTRR_PHYSMASKn. Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5f5edb6ddc83..fb3ea7aad0c1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1747,7 +1747,13 @@ static bool mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) } /* variable MTRRs */ - return valid_mtrr_type(data & 0xff); + WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR)); + + if ((msr & 1) == 0) + /* MTRR base */ + return valid_mtrr_type(data & 0xff); + /* MTRR mask */ + return true; } static int set_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 data)