For filenames that begin with . and are between 2 and 5 characters long, UDF charset conversion code would read uninitialized memory in the output buffer. The only practical impact is that the name may be prepended a "unification hash" when it is not actually needed but still it is good to fix this. Reported-by: syzbot+cd311b1e43cc25f90d18@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/all/000000000000e2638a05fe9dc8f9@xxxxxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> --- fs/udf/unicode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) I plan to merge this fix through my tree. diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c index 622569007b53..2142cbd1dde2 100644 --- a/fs/udf/unicode.c +++ b/fs/udf/unicode.c @@ -247,7 +247,7 @@ static int udf_name_from_CS0(struct super_block *sb, } if (translate) { - if (str_o_len <= 2 && str_o[0] == '.' && + if (str_o_len > 0 && str_o_len <= 2 && str_o[0] == '.' && (str_o_len == 1 || str_o[1] == '.')) needsCRC = 1; if (needsCRC) { -- 2.35.3
