USB: serial: kl5kusb105: fix line-state error handling

The current implementation failed to detect short transfers when
attempting to read the line state, and also, to make things worse,
logged the content of the uninitialised heap transfer buffer.

Fixes: abf492e7b3ae ("USB: kl5kusb105: fix DMA buffers on stack")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index 0ee190fc1bf8ce7154a4a4eac7023a377aa03365..6cb45757818fae2222383358b4d38d7c87b2dbf4 100644 (file)
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -192,10 +192,11 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
                             status_buf, KLSI_STATUSBUF_LEN,
                             10000
                             );
-       if (rc < 0)
-               dev_err(&port->dev, "Reading line status failed (error = %d)\n",
-                       rc);
-       else {
+       if (rc != KLSI_STATUSBUF_LEN) {
+               dev_err(&port->dev, "reading line status failed: %d\n", rc);
+               if (rc >= 0)
+                       rc = -EIO;
+       } else {
                status = get_unaligned_le16(status_buf);
 
                dev_info(&port->serial->dev->dev, "read status %x %x\n",