diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index c93fcaa45d4a..5a15e5478a6b 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -216,6 +216,9 @@ static ssize_t ovl_parse_param_split_lowerdirs(char *str)
 		if (*s == '\\') {
 			/* keep esc chars in split lowerdir */
 			*d++ = *s++;
+			/* A trailing backslash escapes nothing. */
+			if (!*s)
+				return -EINVAL;
 		} else if (*s == ':') {
 			bool next_colon = (*(s + 1) == ':');