USB: serial: ark3116: fix register-accessor error handling

The current implementation failed to detect short transfers, something
which could lead to bits of the uninitialised heap transfer buffer
leaking to user space.

Fixes: 149fc791a4 ("USB: ark3116: Setup some basic infrastructure for
new ark3116 driver.")
Fixes: f4c1e8d597 ("USB: ark3116: Make existing functions 16450-aware
and add close and release functions.")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2017-01-12 14:56:09 +01:00
parent 2c85e0a961
commit 9fef37d7cf

View File

@ -99,10 +99,17 @@ static int ark3116_read_reg(struct usb_serial *serial,
usb_rcvctrlpipe(serial->dev, 0),
0xfe, 0xc0, 0, reg,
buf, 1, ARK_TIMEOUT);
if (result < 0)
if (result < 1) {
dev_err(&serial->interface->dev,
"failed to read register %u: %d\n",
reg, result);
if (result >= 0)
result = -EIO;
return result;
else
return buf[0];
}
return buf[0];
}
static inline int calc_divisor(int bps)