CVE-2013-4535
CVE-2013-4536
Both virtio-block and virtio-serial read,
VirtQueueElements are read in as buffers, and passed to
virtqueue_map_sg(), where num_sg is taken from the wire and can force
writes to indicies beyond VIRTQUEUE_MAX_SIZE.
To fix, validate num_sg.
Reported-by: Michael Roth <mdr...@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/virtio/virtio.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index bcbfbb2..003b6ad 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -430,6 +430,12 @@ void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
unsigned int i;
hwaddr len;
+ if (num_sg >= VIRTQUEUE_MAX_SIZE) {
+ error_report("virtio: map attempt out of bounds: %d > %d",
+ num_sg, VIRTQUEUE_MAX_SIZE);
+ exit(1);
+ }
+
for (i = 0; i < num_sg; i++) {
len = sg[i].iov_len;
sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write);
--
MST
