From: Yuezhang Mo Yuezhang.Mo@sony.com
commit 6cb5d1a16a51d080fbc1649a5144cbc5ca7d6f88 upstream.
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 wangyugui@e16-tech.com Signed-off-by: Yuezhang Mo Yuezhang.Mo@sony.com Reviewed-by: Andy Wu Andy.Wu@sony.com Reviewed-by: Aoyama Wataru wataru.aoyama@sony.com Reviewed-by: Sungjong Seo sj1557.seo@samsung.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/exfat/dir.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
--- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -236,10 +236,7 @@ static int exfat_iterate(struct file *fi 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);