From: Michael S. Tsirkin <mst@redhat.com>
Date: Thu, 3 Apr 2014 16:52:25 +0000 (+0300)
Subject: usb: sanity check setup_index+setup_len in post_load
X-Git-Tag: qemu-xen-4.5.0-rc1^2~97
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=15c35dfd9299733e5391b65efd3e0356a01d01ad;p=qemu-upstream-4.5-testing.git

usb: sanity check setup_index+setup_len in post_load

CVE-2013-4541

s->setup_len and s->setup_index are fed into usb_packet_copy as
size/offset into s->data_buf, it's possible for invalid state to exploit
this to load arbitrary data.

setup_len and setup_index should be checked to make sure
they are not negative.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit 9f8e9895c504149d7048e9fc5eb5cbb34b16e49a)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---

diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index fe7042930..e48b19fc2 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -49,7 +49,9 @@ static int usb_device_post_load(void *opaque, int version_id)
     } else {
         dev->attached = 1;
     }
-    if (dev->setup_index >= sizeof(dev->data_buf) ||
+    if (dev->setup_index < 0 ||
+        dev->setup_len < 0 ||
+        dev->setup_index >= sizeof(dev->data_buf) ||
         dev->setup_len >= sizeof(dev->data_buf)) {
         return -EINVAL;
     }