qemu: Security fix CVE-2015-7295

CVE-2015-7295 Qemu: net: virtio-net possible remote DoS

(From OE-Core rev: 74771f8c41aaede0ddfb86983c6841bd1f1c1f0f)

(From OE-Core rev: 3a7c84952d40f95b0f34bc35eef4490ecc8da07e)

Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/qemu/qemu/CVE-2015-7295_1.patch

@@ -0,0 +1,63 @@
+From ce317461573bac12b10d67699b4ddf1f97cf066c Mon Sep 17 00:00:00 2001
+From: Jason Wang <jasowang@redhat.com>
+Date: Fri, 25 Sep 2015 13:21:28 +0800
+Subject: [PATCH] virtio: introduce virtqueue_unmap_sg()
+
+Factor out sg unmapping logic. This will be reused by the patch that
+can discard descriptor.
+
+Cc: Michael S. Tsirkin <mst@redhat.com>
+Cc: Andrew James <andrew.james@hpe.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=ce317461573bac12b10d67699b4ddf1f97cf066c
+
+CVE: CVE-2015-7295 patch #1
+[Yocto # 9013]
+
+Signed-off-by: Armin Kuster <akuster@mvista.com>
+
+---
+ hw/virtio/virtio.c | 14 ++++++++++----
+ 1 file changed, 10 insertions(+), 4 deletions(-)
+
+Index: qemu-2.2.0/hw/virtio/virtio.c
+===================================================================
+--- qemu-2.2.0.orig/hw/virtio/virtio.c
++++ qemu-2.2.0/hw/virtio/virtio.c
+@@ -240,14 +240,12 @@ int virtio_queue_empty(VirtQueue *vq)
+     return vring_avail_idx(vq) == vq->last_avail_idx;
+ }
+ 
+-void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
+-                    unsigned int len, unsigned int idx)
++static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,
++                               unsigned int len)
+ {
+     unsigned int offset;
+     int i;
+ 
+-    trace_virtqueue_fill(vq, elem, len, idx);
+-
+     offset = 0;
+     for (i = 0; i < elem->in_num; i++) {
+         size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
+@@ -263,6 +261,14 @@ void virtqueue_fill(VirtQueue *vq, const
+         cpu_physical_memory_unmap(elem->out_sg[i].iov_base,
+                                   elem->out_sg[i].iov_len,
+                                   0, elem->out_sg[i].iov_len);
++}
++
++void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
++                    unsigned int len, unsigned int idx)
++{
++    trace_virtqueue_fill(vq, elem, len, idx);
++
++    virtqueue_unmap_sg(vq, elem, len);
+ 
+     idx = (idx + vring_used_idx(vq)) % vq->vring.num;
+ 

meta/recipes-devtools/qemu/qemu/CVE-2015-7295_2.patch

@@ -0,0 +1,58 @@
+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-2.2.0/hw/virtio/virtio.c
+===================================================================
+--- qemu-2.2.0.orig/hw/virtio/virtio.c
++++ qemu-2.2.0/hw/virtio/virtio.c
+@@ -263,6 +263,13 @@ 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-2.2.0/include/hw/virtio/virtio.h
+===================================================================
+--- qemu-2.2.0.orig/include/hw/virtio/virtio.h
++++ qemu-2.2.0/include/hw/virtio/virtio.h
+@@ -180,6 +180,8 @@ 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);
+ 

meta/recipes-devtools/qemu/qemu/CVE-2015-7295_3.patch

@@ -0,0 +1,52 @@
+From 0cf33fb6b49a19de32859e2cdc6021334f448fb3 Mon Sep 17 00:00:00 2001
+From: Jason Wang <jasowang@redhat.com>
+Date: Fri, 25 Sep 2015 13:21:30 +0800
+Subject: [PATCH] virtio-net: correctly drop truncated packets
+
+When packet is truncated during receiving, we drop the packets but
+neither discard the descriptor nor add and signal used
+descriptor. This will lead several issues:
+
+- sg mappings are leaked
+- rx will be stalled if a lots of packets were truncated
+
+In order to be consistent with vhost, fix by discarding the descriptor
+in this case.
+
+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=0cf33fb6b49a19de32859e2cdc6021334f448fb3
+
+CVE: CVE-2015-7295 patch #3
+[Yocto # 9013]
+
+Signed-off-by: Armin Kuster <akuster@mvista.com>
+
+---
+ hw/net/virtio-net.c | 8 +-------
+ 1 file changed, 1 insertion(+), 7 deletions(-)
+
+Index: qemu-2.2.0/hw/net/virtio-net.c
+===================================================================
+--- qemu-2.2.0.orig/hw/net/virtio-net.c
++++ qemu-2.2.0/hw/net/virtio-net.c
+@@ -1070,13 +1070,7 @@ static ssize_t virtio_net_receive(NetCli
+          * must have consumed the complete packet.
+          * Otherwise, drop it. */
+         if (!n->mergeable_rx_bufs && offset < size) {
+-#if 0
+-            error_report("virtio-net truncated non-mergeable packet: "
+-                         "i %zd mergeable %d offset %zd, size %zd, "
+-                         "guest hdr len %zd, host hdr len %zd",
+-                         i, n->mergeable_rx_bufs,
+-                         offset, size, n->guest_hdr_len, n->host_hdr_len);
+-#endif
++            virtqueue_discard(q->rx_vq, &elem, total);
+             return size;
+         }
+ 

meta/recipes-devtools/qemu/qemu_2.2.0.bb

@@ -25,6 +25,9 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \
             file://CVE-2015-7512.patch \
             file://CVE-2015-8345.patch \
             file://CVE-2016-1568.patch \
+            file://CVE-2015-7295_1.patch \
+            file://CVE-2015-7295_2.patch \
+            file://CVE-2015-7295_3.patch \
            "
 SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2"
 SRC_URI[md5sum] = "f7a5e2da22d057eb838a91da7aff43c8"