Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 9 Sep 2020 18:13:16 +0100
From: Al Viro <viro@...iv.linux.org.uk>
To: Mickaël Salaün <mic@...ikod.net>
Cc: linux-kernel@...r.kernel.org, Aleksa Sarai <cyphar@...har.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andy Lutomirski <luto@...nel.org>,
	Christian Brauner <christian.brauner@...ntu.com>,
	Christian Heimes <christian@...hon.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Deven Bowers <deven.desai@...ux.microsoft.com>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	Eric Biggers <ebiggers@...nel.org>,
	Eric Chiang <ericchiang@...gle.com>,
	Florian Weimer <fweimer@...hat.com>,
	James Morris <jmorris@...ei.org>, Jan Kara <jack@...e.cz>,
	Jann Horn <jannh@...gle.com>, Jonathan Corbet <corbet@....net>,
	Kees Cook <keescook@...omium.org>,
	Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>,
	Matthew Garrett <mjg59@...gle.com>,
	Matthew Wilcox <willy@...radead.org>,
	Michael Kerrisk <mtk.manpages@...il.com>,
	Miklos Szeredi <mszeredi@...hat.com>,
	Mimi Zohar <zohar@...ux.ibm.com>,
	Philippe Trébuchet <philippe.trebuchet@....gouv.fr>,
	Scott Shell <scottsh@...rosoft.com>,
	Sean Christopherson <sean.j.christopherson@...el.com>,
	Shuah Khan <shuah@...nel.org>, Steve Dower <steve.dower@...hon.org>,
	Steve Grubb <sgrubb@...hat.com>,
	Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
	Thibaut Sautereau <thibaut.sautereau@...p-os.org>,
	Vincent Strubel <vincent.strubel@....gouv.fr>,
	kernel-hardening@...ts.openwall.com, linux-api@...r.kernel.org,
	linux-integrity@...r.kernel.org,
	linux-security-module@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: [RFC PATCH v8 0/3] Add support for AT_INTERPRETED (was O_MAYEXEC)

On Wed, Sep 09, 2020 at 09:19:11AM +0200, Mickaël Salaün wrote:
> 
> On 08/09/2020 20:50, Al Viro wrote:
> > On Tue, Sep 08, 2020 at 09:59:53AM +0200, Mickaël Salaün wrote:
> >> Hi,
> >>
> >> This height patch series rework the previous O_MAYEXEC series by not
> >> adding a new flag to openat2(2) but to faccessat2(2) instead.  As
> >> suggested, this enables to perform the access check on a file descriptor
> >> instead of on a file path (while opening it).  This may require two
> >> checks (one on open and then with faccessat2) but it is a more generic
> >> approach [8].
> > 
> > Again, why is that folded into lookup/open/whatnot, rather than being
> > an operation applied to a file (e.g. O_PATH one)?
> > 
> 
> I don't understand your question. AT_INTERPRETED can and should be used
> with AT_EMPTY_PATH. The two checks I wrote about was for IMA.

Once more, with feeling: don't hide that behind existing syscalls.
If you want to tell LSM have a look at given fs object in a special
way, *add* *a* *new* *system* *call* *for* *doing* *just* *that*.

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.