[PATCH 3.2 003/185] USB: mos7840: fix tiocmget error handling

Ben Hutchings
2013-12-29T03:04:03Z

From: Johan Hovold <jhovold@gmail.com>

commit a91ccd26e75235d86248d018fe3779732bcafd8d upstream.

Make sure to return errors from tiocmget rather than rely on
uninitialised stack data.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/mos7840.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1689,7 +1689,11 @@ static int mos7840_tiocmget(struct tty_s
return -ENODEV;

status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
+ if (status != 1)
+ return -EIO;
status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
+ if (status != 1)
+ return -EIO;
result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
| ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
| ((mcr & MCR_LOOPBACK) ? TIOCM_LOOP : 0)