If the intention is to overwrite the first NULL with a -1, s[strlen(s)] is the first NULL, not s[strlen(s)+1]. Cc: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> --- fs/unicode/mkutf8data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/unicode/mkutf8data.c b/fs/unicode/mkutf8data.c index bc1a7c8b5c8d..61800e0d3226 100644 --- a/fs/unicode/mkutf8data.c +++ b/fs/unicode/mkutf8data.c @@ -3194,7 +3194,7 @@ static int normalize_line(struct tree *tree) /* Second test: length-limited string. */ s = buf2; /* Replace NUL with a value that will cause an error if seen. */ - s[strlen(s) + 1] = -1; + s[strlen(s)] = -1; t = buf3; if (utf8cursor(&u8c, tree, s)) return -1; -- 2.38.1