"Jason A. Donenfeld" <Jason@xxxxxxxxx> writes: > If the intention is to overwrite the first NUL with a -1, s[strlen(s)] > is the first NUL, not s[strlen(s)+1]. Hi Jason, This code is part of the verification of the trie that done at the end of utf8data generation. It is making sure the tree is not corrupted, by ensuring that utf8byte doesn't see something past the correct end of the string (the first NULL byte). Note it is not a bad memory access either, since we guarantee to have allocated enough space. So I think the code is correct as is. if you apply your patch and regenerate utf8data.h_shipped, utf8byte will reach that -1 and fail the verification. > 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; -- Gabriel Krisman Bertazi
