Commit 00f24465 authored by Johan Hovold's avatar Johan Hovold Committed by Sasha Levin

USB: serial: mct_u232: fix modem-status error handling

[ Upstream commit 36356a66 ]

Make sure to detect short control-message transfers so that errors are
logged when reading the modem status at open.

Note that while this also avoids initialising the modem status using
uninitialised heap data, these bits could not leak to user space as they
are currently not used.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
parent 0379d542
......@@ -322,8 +322,12 @@ static int mct_u232_get_modem_stat(struct usb_serial_port *port,
MCT_U232_GET_REQUEST_TYPE,
0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
WDR_TIMEOUT);
if (rc < 0) {
if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
if (rc >= 0)
rc = -EIO;
*msr = 0;
} else {
*msr = buf[0];
......
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