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>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index bfb3731d42db..2d4fd530e5e4 100644
--- 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;