From 6cb5d1a16a51d080fbc1649a5144cbc5ca7d6f88 Mon Sep 17 00:00:00 2001 From: Yuezhang Mo Date: Thu, 22 Sep 2022 14:43:47 +0800 Subject: exfat: fix unexpected EOF while reading dir If the position is not aligned with the dentry size, the return value of readdir() will be NULL and errno is 0, which means the end of the directory stream is reached. If the position is aligned with dentry size, but there is no file or directory at the position, exfat_readdir() will continue to get dentry from the next dentry. So the dentry gotten by readdir() may not be at the position. After this commit, if the position is not aligned with the dentry size, round the position up to the dentry size and continue to get the dentry. Fixes: ca06197382bd ("exfat: add directory operations") Cc: stable@vger.kernel.org # v5.7+ Reported-by: Wang Yugui Signed-off-by: Yuezhang Mo Reviewed-by: Andy Wu Reviewed-by: Aoyama Wataru Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon --- fs/exfat/dir.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/exfat') diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index 1dfa67f307f1..1122bee3b634 100644 --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -234,10 +234,7 @@ static int exfat_iterate(struct file *file, struct dir_context *ctx) fake_offset = 1; } - if (cpos & (DENTRY_SIZE - 1)) { - err = -ENOENT; - goto unlock; - } + cpos = round_up(cpos, DENTRY_SIZE); /* name buffer should be allocated before use */ err = exfat_alloc_namebuf(nb); -- cgit v1.2.1