From: Al Viro <viro@zeniv.linux.org.uk>
To: Kees Cook <keescook@chromium.org>
Cc: James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] securityfs: Add missing d_delete() call on removal
Date: Wed, 6 May 2020 05:02:52 +0100 [thread overview]
Message-ID: <20200506040252.GC23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <202005052024.2D7626C742@keescook>
On Tue, May 05, 2020 at 08:28:33PM -0700, Kees Cook wrote:
> On Wed, May 06, 2020 at 02:14:31AM +0100, Al Viro wrote:
> > On Tue, May 05, 2020 at 04:40:35PM -0700, Kees Cook wrote:
> > > After using simple_unlink(), a call to d_delete() is needed in addition
> > > to dput().
> > >
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > ---
> > > Is this correct? I went looking around and there are a lot of variations
> > > on the simple_unlink() pattern...
> > >
> > > Many using explicit locking and combinations of d_drop(), __d_drop(), etc.
> >
> > Quite a few of those should switch to simple_recursive_removal(). As for
> > securityfs... d_drop() is _probably_ a saner variant, but looking at the
> > callers of that thing... at least IMA ones seem to be garbage.
>
> Hmm, I dunno. I hadn't looked at these yet. I'm not sure what's needed
> for those cases.
>
> Is my patch to add d_delete() correct, though? I'm trying to construct
> the right set of calls for pstore's filesystem, and I noticed that most
> will do simple_unlink(), d_delete(), dput(), but securityfs seemed to be
> missing it.
d_drop(). d_delete() is for the situations when you want the sucker
to become a hashed negative, if at all possible.
Re pstore: context, please.
next prev parent reply other threads:[~2020-05-06 4:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 23:40 [PATCH] securityfs: Add missing d_delete() call on removal Kees Cook
2020-05-06 1:14 ` Al Viro
2020-05-06 3:28 ` Kees Cook
2020-05-06 4:02 ` Al Viro [this message]
2020-05-06 15:34 ` Kees Cook
2020-05-06 18:49 ` Al Viro
2020-05-06 22:49 ` Kees Cook
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