From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jim Mattson Subject: [PATCH 3/3] kvm: vmx: Check value written to IA32_BNDCFGS Date: Tue, 23 May 2017 11:52:54 -0700 Message-ID: <20170523185254.98780-3-jmattson@google.com> References: <20170523185254.98780-1-jmattson@google.com> Cc: Jim Mattson To: kvm@vger.kernel.org Return-path: Received: from mail-pf0-f175.google.com ([209.85.192.175]:35292 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763521AbdEWSxt (ORCPT ); Tue, 23 May 2017 14:53:49 -0400 Received: by mail-pf0-f175.google.com with SMTP id n23so122940973pfb.2 for ; Tue, 23 May 2017 11:53:48 -0700 (PDT) In-Reply-To: <20170523185254.98780-1-jmattson@google.com> Sender: kvm-owner@vger.kernel.org List-ID: Bits 11:2 must be zero and the linear addess in bits 63:12 must be canonical. Otherwise, WRMSR(BNDCFGS) should raise #GP. Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save") Signed-off-by: Jim Mattson --- arch/x86/include/asm/msr-index.h | 2 ++ arch/x86/kvm/vmx.c | 3 +++ 2 files changed, 5 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 673f9ac50f6d..dbf266b0d14a 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -420,6 +420,8 @@ #define MSR_IA32_TSC_ADJUST 0x0000003b #define MSR_IA32_BNDCFGS 0x00000d90 +#define MSR_IA32_BNDCFGS_RSVD 0x00000ffc + #define MSR_IA32_XSS 0x00000da0 #define FEATURE_CONTROL_LOCKED (1<<0) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 846c60c74258..04d428cd1d9d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3279,6 +3279,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_BNDCFGS: if (!guest_cpuid_has_mpx(vcpu)) return 1; + if (is_noncanonical_address(data & PAGE_MASK) || + (data & MSR_IA32_BNDCFGS_RSVD)) + return 1; vmcs_write64(GUEST_BNDCFGS, data); break; case MSR_IA32_TSC: -- 2.13.0.219.gdb65acc882-goog