rsi: check length before USB read/write register

These checks are required. Otherwise we may end up getting
memory corruption if invalid length is passed.

Fixes: b97e9b94ad75c ("rsi: Add new host interface operations")
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 99a520afc7c5ca7fa0b348058984972ed0856762..3d33ce9ca2baa608e9b7f1984f4d83cbc616fe8f 100644 (file)
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -166,6 +166,9 @@ static int rsi_usb_reg_read(struct usb_device *usbdev,
        if (!buf)
                return status;
 
+       if (len > RSI_USB_CTRL_BUF_SIZE)
+               return -EINVAL;
+
        status = usb_control_msg(usbdev,
                                 usb_rcvctrlpipe(usbdev, 0),
                                 USB_VENDOR_REGISTER_READ,
@@ -208,6 +211,9 @@ static int rsi_usb_reg_write(struct usb_device *usbdev,
        if (!usb_reg_buf)
                return status;
 
+       if (len > RSI_USB_CTRL_BUF_SIZE)
+               return -EINVAL;
+
        usb_reg_buf[0] = (value & 0x00ff);
        usb_reg_buf[1] = (value & 0xff00) >> 8;
        usb_reg_buf[2] = 0x0;