cifs: Allow passwords which begin with a delimitor

Fixes a regression in cifs_parse_mount_options where a password
which begins with a delimitor is parsed incorrectly as being a blank
password.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -1575,14 +1575,24 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 			}
 			break;
 		case Opt_blank_pass:
-			vol->password = NULL;
-			break;
-		case Opt_pass:
 			/* passwords have to be handled differently
 			 * to allow the character used for deliminator
 			 * to be passed within them
 			 */
 
+			/*
+			 * Check if this is a case where the  password
+			 * starts with a delimiter
+			 */
+			tmp_end = strchr(data, '=');
+			tmp_end++;
+			if (!(tmp_end < end && tmp_end[1] == delim)) {
+				/* No it is not. Set the password to NULL */
+				vol->password = NULL;
+				break;
+			}
+			/* Yes it is. Drop down to Opt_pass below.*/
+		case Opt_pass:
 			/* Obtain the value string */
 			value = strchr(data, '=');
 			value++;