diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2014-04-03 19:51:53 +0300 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2014-06-26 14:18:51 -0500 |
| commit | 68801b7be1ddabe3495f68145b1202049b1486c2 (patch) | |
| tree | 0b6510269fe215cc1ac349b4839b9950d83b3167 | |
| parent | 609f5bf6fecb78ada914b88598ae8ba43e304e36 (diff) | |
virtio: validate num_sg when mapping
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 <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit 36cf2a37132c7f01fa9adb5f95f5312b27742fd4)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | hw/virtio/virtio.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 705fad9166..c2c9b5a1ab 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -427,6 +427,12 @@ 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: %zd > %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); |