From: Johan Hovold <johan@xxxxxxxxxx>
[ 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 <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
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 136ff5e1b7c1..135eb04368f9 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