[PATCH] fs/ntfs3: fix an error code in ntfs_get_acl_ex()

From: Dan Carpenter
Date: Tue Aug 24 2021 - 07:49:19 EST


The ntfs_get_ea() function returns negative error codes or on success
it returns the length. In the original code a zero length return was
treated as -ENODATA and results in a NULL return. But it should be
treated as an invalid length and result in an PTR_ERR(-EINVAL) return.

Fixes: be71b5cba2e6 ("fs/ntfs3: Add attrib operations")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
I'm not super familiar with this code. Please review this one
extra carefully. I think it's theoretical because hopefully
ntfs_get_ea() doesn't ever return invalid lengths.

fs/ntfs3/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 9239c388050e..e8ed38d0c4c9 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -521,7 +521,7 @@ static struct posix_acl *ntfs_get_acl_ex(struct user_namespace *mnt_userns,
ni_unlock(ni);

/* Translate extended attribute to acl */
- if (err > 0) {
+ if (err >= 0) {
acl = posix_acl_from_xattr(mnt_userns, buf, err);
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);
--
2.20.1