[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <75442f3b-a3d8-12db-579a-2c5983426b4d@ssi.gouv.fr>
Date: Fri, 6 Sep 2019 18:06:25 +0200
From: Mickaël Salaün <mickael.salaun@....gouv.fr>
To: Florian Weimer <fweimer@...hat.com>, Mickaël Salaün
<mic@...ikod.net>
CC: <linux-kernel@...r.kernel.org>, Aleksa Sarai <cyphar@...har.com>, Alexei
Starovoitov <ast@...nel.org>, Al Viro <viro@...iv.linux.org.uk>, Andy
Lutomirski <luto@...nel.org>, Christian Heimes <christian@...hon.org>, Daniel
Borkmann <daniel@...earbox.net>, Eric Chiang <ericchiang@...gle.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>, 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>, Song Liu <songliubraving@...com>, Steve Dower
<steve.dower@...hon.org>, Steve Grubb <sgrubb@...hat.com>, Thibaut Sautereau
<thibaut.sautereau@....gouv.fr>, Vincent Strubel
<vincent.strubel@....gouv.fr>, Yves-Alexis Perez
<yves-alexis.perez@....gouv.fr>, <kernel-hardening@...ts.openwall.com>,
<linux-api@...r.kernel.org>, <linux-security-module@...r.kernel.org>,
<linux-fsdevel@...r.kernel.org>
Subject: Re: [PATCH v2 1/5] fs: Add support for an O_MAYEXEC flag on
sys_open()
On 06/09/2019 17:56, Florian Weimer wrote:
> Let's assume I want to add support for this to the glibc dynamic loader,
> while still being able to run on older kernels.
>
> Is it safe to try the open call first, with O_MAYEXEC, and if that fails
> with EINVAL, try again without O_MAYEXEC?
The kernel ignore unknown open(2) flags, so yes, it is safe even for
older kernel to use O_MAYEXEC.
>
> Or do I risk disabling this security feature if I do that?
It is only a security feature if the kernel support it, otherwise it is
a no-op.
>
> Do we need a different way for recognizing kernel support. (Note that
> we cannot probe paths in /proc for various reasons.)
There is no need to probe for kernel support.
>
> Thanks,
> Florian
>
--
Mickaël Salaün
Les données à caractère personnel recueillies et traitées dans le cadre de cet échange, le sont à seule fin d’exécution d’une relation professionnelle et s’opèrent dans cette seule finalité et pour la durée nécessaire à cette relation. Si vous souhaitez faire usage de vos droits de consultation, de rectification et de suppression de vos données, veuillez contacter contact.rgpd@...sn.gouv.fr. Si vous avez reçu ce message par erreur, nous vous remercions d’en informer l’expéditeur et de détruire le message. The personal data collected and processed during this exchange aims solely at completing a business relationship and is limited to the necessary duration of that relationship. If you wish to use your rights of consultation, rectification and deletion of your data, please contact: contact.rgpd@...sn.gouv.fr. If you have received this message in error, we thank you for informing the sender and destroying the message.
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.
