USB: don't try to kzalloc 0 bytes

This patch (as907) prevents us from trying to allocate 0 bytes
when an interface has no endpoint descriptors.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index bfb3731..2d4fd53 100644 (file)
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -185,10 +185,12 @@ static int usb_parse_interface(struct device *ddev, int cfgno,
                num_ep = USB_MAXENDPOINTS;
        }
 
-       len = sizeof(struct usb_host_endpoint) * num_ep;
-       alt->endpoint = kzalloc(len, GFP_KERNEL);
-       if (!alt->endpoint)
-               return -ENOMEM;
+       if (num_ep > 0) {       /* Can't allocate 0 bytes */
+               len = sizeof(struct usb_host_endpoint) * num_ep;
+               alt->endpoint = kzalloc(len, GFP_KERNEL);
+               if (!alt->endpoint)
+                       return -ENOMEM;
+       }
 
        /* Parse all the endpoint descriptors */
        n = 0;