Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <26a4a8378f3b4ad28eaa476853092716@AcuMS.aculab.com>
Date: Tue, 11 Aug 2020 08:09:10 +0000
From: David Laight <David.Laight@...LAB.COM>
To: 'Mickaël Salaün' <mic@...ikod.net>, Al Viro
	<viro@...iv.linux.org.uk>
CC: Kees Cook <keescook@...omium.org>, Andrew Morton
	<akpm@...ux-foundation.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, Aleksa Sarai <cyphar@...har.com>, "Alexei
 Starovoitov" <ast@...nel.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>, Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>,
	Matthew Garrett <mjg59@...gle.com>, Matthew Wilcox <willy@...radead.org>,
	Michael Kerrisk <mtk.manpages@...il.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"
	<kernel-hardening@...ts.openwall.com>, "linux-api@...r.kernel.org"
	<linux-api@...r.kernel.org>, "linux-integrity@...r.kernel.org"
	<linux-integrity@...r.kernel.org>, "linux-security-module@...r.kernel.org"
	<linux-security-module@...r.kernel.org>, "linux-fsdevel@...r.kernel.org"
	<linux-fsdevel@...r.kernel.org>
Subject: RE: [PATCH v7 0/7] Add support for O_MAYEXEC

> On 11/08/2020 00:28, Al Viro wrote:
> > On Mon, Aug 10, 2020 at 10:09:09PM +0000, David Laight wrote:
> >>> On Mon, Aug 10, 2020 at 10:11:53PM +0200, Mickaël Salaün wrote:
> >>>> It seems that there is no more complains nor questions. Do you want me
> >>>> to send another series to fix the order of the S-o-b in patch 7?
> >>>
> >>> There is a major question regarding the API design and the choice of
> >>> hooking that stuff on open().  And I have not heard anything resembling
> >>> a coherent answer.
> >>
> >> To me O_MAYEXEC is just the wrong name.
> >> The bit would be (something like) O_INTERPRET to indicate
> >> what you want to do with the contents.
> 
> The properties is "execute permission". This can then be checked by
> interpreters or other applications, then the generic O_MAYEXEC name.

The english sense of MAYEXEC is just wrong for what you are trying
to check.

> > ... which does not answer the question - name of constant is the least of
> > the worries here.  Why the hell is "apply some unspecified checks to
> > file" combined with opening it, rather than being an independent primitive
> > you apply to an already opened file?  Just in case - "'cuz that's how we'd
> > done it" does not make a good answer...

Maybe an access_ok() that acts on an open fd would be more
appropriate.
Which might end up being an fcntrl() action.
That would give you a full 32bit mask of options.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

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.