staging: vt6655: buffer overflow in ioctl

->u.generic_elem.len is a user controlled number between 0-255. We
should limit it to avoid memory corruption.

Signed-off-by: Dan Carpenter <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/vt6655/hostap.c

···
 {
 	PSMgmtObject    pMgmt = pDevice->pMgmt;
 
+	if (param->u.generic_elem.len > sizeof(pMgmt->abyWPAIE))
+		return -EINVAL;
+
 	memcpy(pMgmt->abyWPAIE,
 	       param->u.generic_elem.data,
 	       param->u.generic_elem.len