USB: cdc-acm: signedness fix
Fix bogus assignment of "unsigned char *" to "char *": preserve
unsignedness. These values are used directly as descriptor lengths
when iterating through the buffer, so this *could* cause oddness
that potentially includes oopsing. (IMO not likely, except as
part of a malicious device...)
Fix the bogus warning in CDC ACM which highlighted this problem
(by showing a negative descriptor type). It uses the undesirable
legacy err() for something that's not even an error; switch to
use dev_dbg, and show descriptor types in hex notation to match
the convention for such codes.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index d9b4081..6d57413 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -804,7 +804,7 @@
{
struct usb_cdc_union_desc *union_header = NULL;
struct usb_cdc_country_functional_desc *cfd = NULL;
- char *buffer = intf->altsetting->extra;
+ unsigned char *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
struct usb_interface *control_interface;
struct usb_interface *data_interface;
@@ -881,9 +881,13 @@
if ((call_management_function & 3) != 3)
err("This device cannot do calls on its own. It is no modem.");
break;
-
default:
- err("Ignoring extra header, type %d, length %d", buffer[2], buffer[0]);
+ /* there are LOTS more CDC descriptors that
+ * could legitimately be found here.
+ */
+ dev_dbg(&intf->dev, "Ignoring descriptor: "
+ "type %02x, length %d\n",
+ buffer[2], buffer[0]);
break;
}
next_desc: