--- /dev/null
+From 7e46dddd6f6cd5dbf3c7bd04a7e75d19475ac9f2 Mon Sep 17 00:00:00 2001
+From: Nadav Amit <namit@cs.technion.ac.il>
+Date: Tue, 28 Oct 2014 00:03:43 +0200
+Subject: KVM: x86: Fix far-jump to non-canonical check
+
+From: Nadav Amit <namit@cs.technion.ac.il>
+
+commit 7e46dddd6f6cd5dbf3c7bd04a7e75d19475ac9f2 upstream.
+
+Commit d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far
+jumps") introduced a bug that caused the fix to be incomplete. Due to
+incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit
+segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may
+not trigger #GP. As we know, this imposes a security problem.
+
+In addition, the condition for two warnings was incorrect.
+
+Fixes: d1442d85cc30ea75f7d399474ca738e0bc96f715
+Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
+Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
+[Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo]
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/kvm/emulate.c | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+--- a/arch/x86/kvm/emulate.c
++++ b/arch/x86/kvm/emulate.c
+@@ -573,12 +573,14 @@ static inline int assign_eip_far(struct
+ case 4:
+ ctxt->_eip = (u32)dst;
+ break;
++#ifdef CONFIG_X86_64
+ case 8:
+ if ((cs_l && is_noncanonical_address(dst)) ||
+- (!cs_l && (dst & ~(u32)-1)))
++ (!cs_l && (dst >> 32) != 0))
+ return emulate_gp(ctxt, 0);
+ ctxt->_eip = dst;
+ break;
++#endif
+ default:
+ WARN(1, "unsupported eip assignment size\n");
+ }
+@@ -2026,7 +2028,7 @@ static int em_jmp_far(struct x86_emulate
+
+ rc = assign_eip_far(ctxt, ctxt->src.val, new_desc.l);
+ if (rc != X86EMUL_CONTINUE) {
+- WARN_ON(!ctxt->mode != X86EMUL_MODE_PROT64);
++ WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
+ /* assigning eip failed; restore the old cs */
+ ops->set_segment(ctxt, old_sel, &old_desc, 0, VCPU_SREG_CS);
+ return rc;
+@@ -2123,7 +2125,7 @@ static int em_ret_far(struct x86_emulate
+ return rc;
+ rc = assign_eip_far(ctxt, eip, new_desc.l);
+ if (rc != X86EMUL_CONTINUE) {
+- WARN_ON(!ctxt->mode != X86EMUL_MODE_PROT64);
++ WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
+ ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
+ }
+ return rc;