USB: fix double frees in error code paths of ipaq driver

the error code paths can be enter with buffers to freed buffers.
Serial core would do a kfree() on memory already freed.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
index 6a3a704b5849..c1a6484f6524 100644
--- a/drivers/usb/serial/ipaq.c
+++ b/drivers/usb/serial/ipaq.c
@@ -646,11 +646,13 @@ static int ipaq_open(struct usb_serial_port *port, struct file *filp)
         kfree(port->bulk_out_buffer);
         port->bulk_in_buffer = kmalloc(URBDATA_SIZE, GFP_KERNEL);
         if (port->bulk_in_buffer == NULL) {
+                port->bulk_out_buffer = NULL; /* prevent double free */
                 goto enomem;
         }
         port->bulk_out_buffer = kmalloc(URBDATA_SIZE, GFP_KERNEL);
         if (port->bulk_out_buffer == NULL) {
                 kfree(port->bulk_in_buffer);
+                port->bulk_in_buffer = NULL;
                 goto enomem;
         }
         port->read_urb->transfer_buffer = port->bulk_in_buffer;