diff mbox

[097/108] virtio: out-of-bounds buffer write on invalid state load

Message ID 1407357598-21541-98-git-send-email-mdroth@linux.vnet.ibm.com
State New
Headers show

Commit Message

Michael Roth Aug. 6, 2014, 8:39 p.m. UTC 
From: "Michael S. Tsirkin" <mst@redhat.com>

CVE-2013-4151 QEMU 1.0 out-of-bounds buffer write in
virtio_load@hw/virtio/virtio.c

So we have this code since way back when:

    num = qemu_get_be32(f);

    for (i = 0; i < num; i++) {
        vdev->vq[i].vring.num = qemu_get_be32(f);

array of vqs has size VIRTIO_PCI_QUEUE_MAX, so
on invalid input this will write beyond end of buffer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit cc45995294b92d95319b4782750a3580cabdbc0c)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/virtio/virtio.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 6523e62..d5837c5 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -897,7 +897,8 @@  int virtio_set_features(VirtIODevice *vdev, uint32_t val)
 
 int virtio_load(VirtIODevice *vdev, QEMUFile *f)
 {
-    int num, i, ret;
+    int i, ret;
+    uint32_t num;
     uint32_t features;
     uint32_t supported_features;
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
@@ -928,6 +929,11 @@  int virtio_load(VirtIODevice *vdev, QEMUFile *f)
 
     num = qemu_get_be32(f);
 
+    if (num > VIRTIO_PCI_QUEUE_MAX) {
+        error_report("Invalid number of PCI queues: 0x%x", num);
+        return -1;
+    }
+
     for (i = 0; i < num; i++) {
         vdev->vq[i].vring.num = qemu_get_be32(f);
         if (k->has_variable_vring_alignment) {