On Tue, Apr 2, 2024 at 3:39 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
...
> But if we really want to do this ("if mknod creates a positive dentry,
> I won't see it in lookup, so I want to appraise it now"), then we
> should just deal with this in the generic layer with some hack like
> this:
>
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1801,7 +1801,8 @@ EXPORT_SYMBOL(security_path_mknod);
> */
> void security_path_post_mknod(struct mnt_idmap *idmap, struct dentry *dentry)
> {
> - if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
> + struct inode *inode = d_backing_inode(dentry);
> + if (unlikely(!inode || IS_PRIVATE(inode)))
> return;
> call_void_hook(path_post_mknod, idmap, dentry);
> }
Other than your snippet wrapping both the inode/NULL and
inode/IS_PRIVATE checks with an unlikely(), that's what Roberto
submitted (his patch only wrapped the inode/IS_PRIVATE with unlikely).
--
paul-moore.com
