From 0d1b459a0baf87c8cd5ec8d8e1acb7d15fb60b9f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 12 Jan 2017 14:56:17 +0100 Subject: [PATCH] USB: serial: mos7720: fix control-message error handling [ Upstream commit 0d130367abf582e7cbf60075c2a7ab53817b1d14 ] Make sure to log an error on short transfers when reading a device register. Also clear the provided buffer (which if often an uninitialised automatic variable) on errors as the driver currently does not bother to check for errors. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mos7720.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c index e56cdb436de3..4581fa1dec98 100644 --- a/drivers/usb/serial/mos7720.c +++ b/drivers/usb/serial/mos7720.c @@ -234,11 +234,16 @@ static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum, status = usb_control_msg(usbdev, pipe, request, requesttype, value, index, buf, 1, MOS_WDR_TIMEOUT); - if (status == 1) + if (status == 1) { *data = *buf; - else if (status < 0) + } else { dev_err(&usbdev->dev, "mos7720: usb_control_msg() failed: %d\n", status); + if (status >= 0) + status = -EIO; + *data = 0; + } + kfree(buf); return status; -- 2.11.0