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

commit 146cc8a17a3b4996f6805ee5c080e7101277c410 upstream.

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")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index cd0322502ab192ea78c2bbc5584b4a2b78b9daeb..83c823d32ff96e5af5379dba5a5017245a541681 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",