5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jan Kara jack@suse.cz
[ Upstream commit 028f6055c912588e6f72722d89c30b401bbcf013 ]
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@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/000000000000e2638a05fe9dc8f9@google.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- fs/udf/unicode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c index 622569007b530..2142cbd1dde24 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) {