From 29b9f5efd78ae0f9cc02dd169b6e80d2c404bade Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Fri, 25 Sep 2015 13:21:29 +0800
Subject: [PATCH] virtio: introduce virtqueue_discard()
This patch introduces virtqueue_discard() to discard a descriptor and
unmap the sgs. This will be used by the patch that will discard
descriptor when packet is truncated.
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Upstream-Status: Backport
git.qemu.org/?p=qemu.git;a=commit;h=29b9f5efd78ae0f9cc02dd169b6e80d2c404bade
CVE: CVE-2015-7295 patch #2
[Yocto # 9013]
Signed-off-by: Armin Kuster <akuster@mvista.com>
---
hw/virtio/virtio.c | 7 +++++++
include/hw/virtio/virtio.h | 2 ++
2 files changed, 9 insertions(+)
Index: qemu-2.4.0/hw/virtio/virtio.c
===================================================================
--- qemu-2.4.0.orig/hw/virtio/virtio.c
+++ qemu-2.4.0/hw/virtio/virtio.c
@@ -266,6 +266,13 @@ static void virtqueue_unmap_sg(VirtQueue
0, elem->out_sg[i].iov_len);
}
+void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem,
+ unsigned int len)
+{
+ vq->last_avail_idx--;
+ virtqueue_unmap_sg(vq, elem, len);
+}
+
void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx)
{
Index: qemu-2.4.0/include/hw/virtio/virtio.h
===================================================================
--- qemu-2.4.0.orig/include/hw/virtio/virtio.h
+++ qemu-2.4.0/include/hw/virtio/virtio.h
@@ -146,6 +146,8 @@ void virtio_del_queue(VirtIODevice *vdev
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len);
void virtqueue_flush(VirtQueue *vq, unsigned int count);
+void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem,
+ unsigned int len);
void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx);