[PATCH] drivers/usb/serial/opticon.c: Release resources on kmalloc failure

[Julia Lawall <julia@diku.dk>]

From: Julia Lawall <julia@diku.dk>

Several resources have been allocated before this kmalloc failure, and thus
they should be released in this error handling code, as done in nearby
error handling code.

The semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression urb;
statement S;
position p1,p2;
@@

urb = usb_alloc_urb@p1(...);
... when != urb
if (urb == NULL) S
... when != urb
(
return <+...urb...+>;
|
return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

cocci.print_main("",p1)
cocci.print_secs("",p2)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/usb/serial/opticon.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 1b5633f..96423f3 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -289,8 +289,11 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 	/* The conncected devices do not have a bulk write endpoint,
 	 * to transmit data to de barcode device the control endpoint is used */
 	dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
-	if (!dr)
-		return -ENOMEM;
+	if (!dr) {
+		dev_err(&port->dev, "out of memory\n");
+		count = -ENOMEM;
+		goto error;
+	}
 
 	dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 	dr->bRequest = 0x01;