Add an assert and an explicit check before the two callers to
usb_ep_get() in the USB redirector code to ensure the device
passed in is not NULL.

Signed-off-by: Liam Merwick <liam.merwick@oracle.com>
---
 hw/usb/redirect.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 18a42d19380e..7cb6b120d4f0 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -1728,6 +1728,7 @@ static void usbredir_ep_info(void *priv,
     USBRedirDevice *dev = priv;
     int i;
 
+    assert(dev != NULL);
     for (i = 0; i < MAX_ENDPOINTS; i++) {
         dev->endpoint[i].type = ep_info->type[i];
         dev->endpoint[i].interval = ep_info->interval[i];
@@ -2125,7 +2126,7 @@ static int usbredir_post_load(void *priv, int version_id)
 {
     USBRedirDevice *dev = priv;
 
-    if (dev->parser == NULL) {
+    if (dev == NULL || dev->parser == NULL) {
         return 0;
     }
 
-- 
1.8.3.1