USB: fix oops in cdc-wdm in case of malformed descriptors

upstream commit: e13c594f3a1fc2c78e7a20d1a07974f71e4b448f

cdc-wdm needs to ignore extremely malformed descriptors.

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 3771d6e6d0ccb95587c2bf3ca9de5e6fdf492348..34e6108e1d42bfd879ed28df0ed00e2d2f538425 100644 (file)
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -652,7 +652,7 @@ next_desc:
 
        iface = &intf->altsetting[0];
        ep = &iface->endpoint[0].desc;
-       if (!usb_endpoint_is_int_in(ep)) {
+       if (!ep || !usb_endpoint_is_int_in(ep)) {
                rv = -EINVAL;
                goto err;
        }