From: "Mickaël Salaün" <mic@digikod.net>
To: Randy Dunlap <rdunlap@infradead.org>, linux-kernel@vger.kernel.org
Cc: "Aleksa Sarai" <cyphar@cyphar.com>,
"Alexei Starovoitov" <ast@kernel.org>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Andy Lutomirski" <luto@kernel.org>,
"Christian Brauner" <christian.brauner@ubuntu.com>,
"Christian Heimes" <christian@python.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Deven Bowers" <deven.desai@linux.microsoft.com>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Eric Biggers" <ebiggers@kernel.org>,
"Eric Chiang" <ericchiang@google.com>,
"Florian Weimer" <fweimer@redhat.com>,
"James Morris" <jmorris@namei.org>, "Jan Kara" <jack@suse.cz>,
"Jann Horn" <jannh@google.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Kees Cook" <keescook@chromium.org>,
"Lakshmi Ramasubramanian" <nramas@linux.microsoft.com>,
"Matthew Garrett" <mjg59@google.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Michael Kerrisk" <mtk.manpages@gmail.com>,
"Mickaël Salaün" <mickael.salaun@ssi.gouv.fr>,
"Mimi Zohar" <zohar@linux.ibm.com>,
"Philippe Trébuchet" <philippe.trebuchet@ssi.gouv.fr>,
"Scott Shell" <scottsh@microsoft.com>,
"Sean Christopherson" <sean.j.christopherson@intel.com>,
"Shuah Khan" <shuah@kernel.org>,
"Steve Dower" <steve.dower@python.org>,
"Steve Grubb" <sgrubb@redhat.com>,
"Tetsuo Handa" <penguin-kernel@I-love.SAKURA.ne.jp>,
"Thibaut Sautereau" <thibaut.sautereau@ssi.gouv.fr>,
"Vincent Strubel" <vincent.strubel@ssi.gouv.fr>,
kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v6 5/7] fs,doc: Enable to enforce noexec mounts or file exec through O_MAYEXEC
Date: Thu, 16 Jul 2020 16:40:56 +0200 [thread overview]
Message-ID: <67fe6c17-a0b3-5c7e-a7c8-4c2b6e0c0592@digikod.net> (raw)
In-Reply-To: <038639b1-92da-13c1-b3e5-8f13639a815e@infradead.org>
On 14/07/2020 20:40, Randy Dunlap wrote:
> Hi,
>
> On 7/14/20 11:16 AM, Mickaël Salaün wrote:
>
>> ---
>> Documentation/admin-guide/sysctl/fs.rst | 45 +++++++++++++++++++++++++
>> fs/namei.c | 29 +++++++++++++---
>> include/linux/fs.h | 1 +
>> kernel/sysctl.c | 12 +++++--
>> 4 files changed, 80 insertions(+), 7 deletions(-)
>>
>> diff --git a/Documentation/admin-guide/sysctl/fs.rst b/Documentation/admin-guide/sysctl/fs.rst
>> index 2a45119e3331..02ec384b8bbf 100644
>> --- a/Documentation/admin-guide/sysctl/fs.rst
>> +++ b/Documentation/admin-guide/sysctl/fs.rst
>
> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
>
> with one tiny nit:
>
>> @@ -165,6 +166,50 @@ system needs to prune the inode list instead of allocating
>> +The ability to restrict code execution must be thought as a system-wide policy,
>> +which first starts by restricting mount points with the ``noexec`` option.
>> +This option is also automatically applied to special filesystems such as /proc
>> +. This prevents files on such mount points to be directly executed by the
>
> Can you move that period from the beginning of the line to the end of the
> previous line?
OK, done. Thanks!
>
>> +kernel or mapped as executable memory (e.g. libraries). With script
>> +interpreters using the ``O_MAYEXEC`` flag, the executable permission can then
>> +be checked before reading commands from files. This makes it possible to
>> +enforce the ``noexec`` at the interpreter level, and thus propagates this
>> +security policy to scripts. To be fully effective, these interpreters also
>> +need to handle the other ways to execute code: command line parameters (e.g.,
>> +option ``-e`` for Perl), module loading (e.g., option ``-m`` for Python),
>> +stdin, file sourcing, environment variables, configuration files, etc.
>> +According to the threat model, it may be acceptable to allow some script
>> +interpreters (e.g. Bash) to interpret commands from stdin, may it be a TTY or a
>> +pipe, because it may not be enough to (directly) perform syscalls.
>
> thanks.
>
next prev parent reply other threads:[~2020-07-16 14:41 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 18:16 [PATCH v6 0/7] Add support for O_MAYEXEC Mickaël Salaün
2020-07-14 18:16 ` [PATCH v6 1/7] exec: Change uselib(2) IS_SREG() failure to EACCES Mickaël Salaün
2020-07-14 18:16 ` [PATCH v6 2/7] exec: Move S_ISREG() check earlier Mickaël Salaün
2020-07-14 18:16 ` [PATCH v6 3/7] exec: Move path_noexec() " Mickaël Salaün
2020-07-14 18:16 ` [PATCH v6 4/7] fs: Introduce O_MAYEXEC flag for openat2(2) Mickaël Salaün
2020-07-15 20:06 ` Kees Cook
2020-07-16 14:18 ` Mickaël Salaün
2020-07-16 15:31 ` Kees Cook
2020-07-14 18:16 ` [PATCH v6 5/7] fs,doc: Enable to enforce noexec mounts or file exec through O_MAYEXEC Mickaël Salaün
2020-07-14 18:40 ` Randy Dunlap
2020-07-16 14:40 ` Mickaël Salaün [this message]
2020-07-15 20:37 ` Kees Cook
2020-07-16 14:39 ` Mickaël Salaün
2020-07-22 16:16 ` Thibaut Sautereau
2020-07-22 19:04 ` Mickaël Salaün
2020-07-22 19:40 ` Kees Cook
2020-07-14 18:16 ` [PATCH v6 6/7] selftest/openat2: Add tests for O_MAYEXEC enforcing Mickaël Salaün
2020-07-15 20:38 ` Kees Cook
2020-07-14 18:16 ` [PATCH v6 7/7] ima: add policy support for the new file open MAY_OPENEXEC flag Mickaël Salaün
2020-07-15 20:40 ` Kees Cook
2020-07-16 14:40 ` Mickaël Salaün
2020-07-16 14:59 ` Randy Dunlap
2020-07-16 15:22 ` Mickaël Salaün
2020-07-16 19:13 ` Kees Cook
2020-07-16 19:12 ` Kees Cook
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=67fe6c17-a0b3-5c7e-a7c8-4c2b6e0c0592@digikod.net \
--to=mic@digikod.net \
--cc=akpm@linux-foundation.org \
--cc=ast@kernel.org \
--cc=christian.brauner@ubuntu.com \
--cc=christian@python.org \
--cc=corbet@lwn.net \
--cc=cyphar@cyphar.com \
--cc=daniel@iogearbox.net \
--cc=deven.desai@linux.microsoft.com \
--cc=dvyukov@google.com \
--cc=ebiggers@kernel.org \
--cc=ericchiang@google.com \
--cc=fweimer@redhat.com \
--cc=jack@suse.cz \
--cc=jannh@google.com \
--cc=jmorris@namei.org \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mickael.salaun@ssi.gouv.fr \
--cc=mjg59@google.com \
--cc=mtk.manpages@gmail.com \
--cc=nramas@linux.microsoft.com \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=philippe.trebuchet@ssi.gouv.fr \
--cc=rdunlap@infradead.org \
--cc=scottsh@microsoft.com \
--cc=sean.j.christopherson@intel.com \
--cc=sgrubb@redhat.com \
--cc=shuah@kernel.org \
--cc=steve.dower@python.org \
--cc=thibaut.sautereau@ssi.gouv.fr \
--cc=vincent.strubel@ssi.gouv.fr \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).