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

[Dan Carpenter]

On Tue, Aug 24, 2021 at 07:38:51PM +0300, Kari Argillander wrote:
> On Tue, Aug 24, 2021 at 02:48:58PM +0300, Dan Carpenter wrote:
> > 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) {
> 
> So now if err (size) is 0 it will try to get acl. Didn't you just say
> that you want to return PTR_ERR(-EINVAL)?
> 

If you pass an invalid too short size to posix_acl_from_xattr() then it
returns PTR_ERR(-EINVAL).  It was hard to phrase this in the change log
but I feel like length of 1 and 0 should be treated the same.


> So overall good finding but maybe more work is needed with this one.
> 
> >  		acl = posix_acl_from_xattr(mnt_userns, buf, err);
> >  		if (!IS_ERR(acl))
> >  			set_cached_acl(inode, type, acl);

regards,
dan carpenter