From 6ffa92ffaed817cea7625ebf9c7f217e293923be Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Tue, 23 May 2017 11:52:54 -0700 Subject: kvm: vmx: Check value written to IA32_BNDCFGS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 4531662d1abf6c1f0e5c2b86ddb60e61509786c8 upstream. 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 Signed-off-by: Radim Krčmář Signed-off-by: Greg Kroah-Hartman --- 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 690b4027e17c..37db36fddc88 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -405,6 +405,8 @@ #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 3d776b625766..a2dd5a5ee472 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2891,6 +2891,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_BNDCFGS: if (!kvm_mpx_supported() || !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: -- cgit v1.2.3