Patch "KVM: x86: zero base3 of unusable segments" has been added to the 4.9-stable tree

Patch "KVM: x86: zero base3 of unusable segments" has been added to the 4.9-stable tree

[gregkh]

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

    KVM: x86: zero base3 of unusable segments

to the 4.9-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-x86-zero-base3-of-unusable-segments.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f0367ee1d64d27fa08be2407df5c125442e885e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>
Date: Thu, 18 May 2017 19:37:30 +0200
Subject: KVM: x86: zero base3 of unusable segments
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Radim Krčmář <rkrcmar@redhat.com>

commit f0367ee1d64d27fa08be2407df5c125442e885e3 upstream.

Static checker noticed that base3 could be used uninitialized if the
segment was not present (useable).  Random stack values probably would
not pass VMCS entry checks.

Reported-by:  Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 1aa366163b8b ("KVM: x86 emulator: consolidate segment accessors")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/x86.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4999,6 +4999,8 @@ static bool emulator_get_segment(struct
 
 	if (var.unusable) {
 		memset(desc, 0, sizeof(*desc));
+		if (base3)
+			*base3 = 0;
 		return false;
 	}
 


Patches currently in stable-queue which might be from rkrcmar@redhat.com are

queue-4.9/kvm-nvmx-fix-exception-injection.patch
queue-4.9/kvm-x86-vpmu-fix-undefined-shift-in-intel_pmu_refresh.patch
queue-4.9/kvm-x86-zero-base3-of-unusable-segments.patch
queue-4.9/kvm-x86-fix-fixing-of-hypercalls.patch