Patch "kvm: vmx: Check value written to IA32_BNDCFGS" has been added to the 4.12-stable tree

This is a note to let you know that I've just added the patch titled

kvm: vmx: Check value written to IA32_BNDCFGS

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-vmx-check-value-written-to-ia32_bndcfgs.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jim Mattson <[email protected]>
Date: Tue, 23 May 2017 11:52:54 -0700
Subject: kvm: vmx: Check value written to IA32_BNDCFGS
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From: Jim Mattson <[email protected]>

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.

---
 arch/x86/include/asm/msr-index.h |    2 ++
 arch/x86/kvm/vmx.c               |    3 +++
 2 files changed, 5 insertions(+)

@@ -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)

@@ -3279,6 +3279,9 @@ static int vmx_set_msr(struct kvm_vcpu *
 	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:

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/kvm-x86-guest-bndcfgs-requires-guest-mpx-support.patch queue-4.12/kvm-vmx-check-value-written-to-ia32_bndcfgs.patch queue-4.12/kvm-vmx-do-not-disable-intercepts-for-bndcfgs.patch