From: Johan Hovold <jo...@kernel.org>
[ Upstream commit cd8db057e93ddaacbec025b567490555d2bca280 ]
Make sure to detect short transfers when reading a device register.
The modem-status handling had sufficient error checks in place, but move
handling of short transfers into the register accessor function itself
for consistency.
Reviewed-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Johan Hovold <jo...@kernel.org>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
---
drivers/usb/serial/mos7840.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 0b547d9e2aeb..a0dca81dfaca 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -285,9 +285,15 @@ static int mos7840_get_reg_sync(struct usb_serial_port
*port, __u16 reg,
ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
MCS_RD_RTYPE, 0, reg, buf, VENDOR_READ_LENGTH,
MOS_WDR_TIMEOUT);
+ if (ret < VENDOR_READ_LENGTH) {
+ if (ret >= 0)
+ ret = -EIO;
+ goto out;
+ }
+
*val = buf[0];
dev_dbg(&port->dev, "%s offset is %x, return val %x\n", __func__, reg,
*val);
-
+out:
kfree(buf);
return ret;
}
@@ -353,8 +359,13 @@ static int mos7840_get_uart_reg(struct usb_serial_port
*port, __u16 reg,
ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
MCS_RD_RTYPE, Wval, reg, buf, VENDOR_READ_LENGTH,
MOS_WDR_TIMEOUT);
+ if (ret < VENDOR_READ_LENGTH) {
+ if (ret >= 0)
+ ret = -EIO;
+ goto out;
+ }
*val = buf[0];
-
+out:
kfree(buf);
return ret;
}
@@ -1518,10 +1529,10 @@ static int mos7840_tiocmget(struct tty_struct *tty)
return -ENODEV;
status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
- if (status != 1)
+ if (status < 0)
return -EIO;
status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
- if (status != 1)
+ if (status < 0)
return -EIO;
result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
| ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
--
2.11.0
