From: Jim Mattson Date: Tue, 23 May 2017 18:52:54 +0000 (-0700) Subject: kvm: vmx: Check value written to IA32_BNDCFGS X-Git-Tag: v4.11.12~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bedb27f7481485fee092611409da00f1ce345c4a;p=thirdparty%2Fkernel%2Fstable.git kvm: vmx: Check value written to IA32_BNDCFGS 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 --- diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index d8b5f8ab8ef9e..526d0606bd720 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -417,6 +417,8 @@ #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 f57cb92704780..f5b9dae409e75 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3284,6 +3284,9 @@ 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: