[gentoo-commits] proj/qemu-kvm:qemu-kvm-0.14.1-gentoo commit in: hw/

["Doug Goldstein" <cardoe@gentoo.org>]

commit:     35e17b6a41b1d1126f7f68b835b227805404440d
Author:     Nelson Elhage <&lt;nelhage <AT> ksplice <DOT> com&gt>
AuthorDate: Thu May 19 17:23:17 2011 +0000
Commit:     Doug Goldstein <cardoe <AT> gentoo <DOT> org>
CommitDate: Thu Jul 21 20:22:39 2011 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/qemu-kvm.git;a=commit;h=35e17b6a

virtqueue: Sanity-check the length of indirect descriptors.

We were previously allowing arbitrarily-long descriptors, which could lead to a
buffer overflow in the qemu-kvm process.

---
 hw/virtio.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/hw/virtio.c b/hw/virtio.c
index 31bd9e3..a91a28b 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -336,6 +336,11 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
             max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
             num_bufs = i = 0;
             desc_pa = vring_desc_addr(desc_pa, i);
+
+            if (max &gt; VIRTQUEUE_MAX_SIZE) {
+                error_report(&quot;Too-large indirect descriptor&quot;);
+                exit(1);
+            }
         }
 
         do {
@@ -406,6 +411,11 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
         max = vring_desc_len(desc_pa, i) / sizeof(VRingDesc);
         desc_pa = vring_desc_addr(desc_pa, i);
         i = 0;
+
+        if (max &gt; VIRTQUEUE_MAX_SIZE) {
+            error_report(&quot;Too-large indirect descriptor&quot;);
+            exit(1);
+        }
     }
 
     /* Collect all the descriptors */