1 files changed, 45 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-KVM-x86-Add-memory-barrier-on-vmcs-field-lookup.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-KVM-x86-Add-memory-barrier-on-vmcs-field-lookup.patch
new file mode 100644
index 00000000..b53db2f4
--- /dev/null
+++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-KVM-x86-Add-memory-barrier-on-vmcs-field-lookup.patch
@@ -0,0 +1,45 @@
+From ab442dfc820b6ebdbb1c135e6fad66130d44e5a8 Mon Sep 17 00:00:00 2001
+From: Andrew Honig <ahonig@google.com>
+Date: Wed, 10 Jan 2018 10:12:03 -0800
+Subject: [PATCH 03/33] KVM: x86: Add memory barrier on vmcs field lookup
+
+commit 75f139aaf896d6fdeec2e468ddfa4b2fe469bf40 upstream.
+
+This adds a memory barrier when performing a lookup into
+the vmcs_field_to_offset_table.  This is related to
+CVE-2017-5753.
+
+Signed-off-by: Andrew Honig <ahonig@google.com>
+Reviewed-by: Jim Mattson <jmattson@google.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kvm/vmx.c | 12 ++++++++++--
+ 1 file changed, 10 insertions(+), 2 deletions(-)
+
+diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
+index 91ae4e2..ee766c2 100644
+--- a/arch/x86/kvm/vmx.c
++++ b/arch/x86/kvm/vmx.c
+@@ -858,8 +858,16 @@ static inline short vmcs_field_to_offset(unsigned long field)
+ {
+ 	BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX);
+ 
+-	if (field >= ARRAY_SIZE(vmcs_field_to_offset_table) ||
+-	    vmcs_field_to_offset_table[field] == 0)
++	if (field >= ARRAY_SIZE(vmcs_field_to_offset_table))
++		return -ENOENT;
++
++	/*
++	 * FIXME: Mitigation for CVE-2017-5753.  To be replaced with a
++	 * generic mechanism.
++	 */
++	asm("lfence");
++
++	if (vmcs_field_to_offset_table[field] == 0)
+ 		return -ENOENT;
+ 
+ 	return vmcs_field_to_offset_table[field];
+-- 
+2.7.4
+