[v2,0/1] Unprivileged chroot

Message ID	20210310181857.401675-1-mic@digikod.net (mailing list archive)
Headers	show Return-Path: <linux-security-module-owner@kernel.org> From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= <mic@digikod.net> To: Al Viro <viro@zeniv.linux.org.uk>, James Morris <jmorris@namei.org>, Serge Hallyn <serge@hallyn.com> Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= <mic@digikod.net>, Andy Lutomirski <luto@amacapital.net>, Casey Schaufler <casey@schaufler-ca.com>, Christian Brauner <christian.brauner@ubuntu.com>, Christoph Hellwig <hch@lst.de>, David Howells <dhowells@redhat.com>, Dominik Brodowski <linux@dominikbrodowski.net>, "Eric W . Biederman" <ebiederm@xmission.com>, John Johansen <john.johansen@canonical.com>, Kees Cook <keescook@chromium.org>, Kentaro Takeda <takedakn@nttdata.co.jp>, Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>, kernel-hardening@lists.openwall.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 0/1] Unprivileged chroot Date: Wed, 10 Mar 2021 19:18:56 +0100 Message-Id: <20210310181857.401675-1-mic@digikod.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Unprivileged chroot \| expand [v2,0/1] Unprivileged chroot [v2,1/1] fs: Allow no_new_privs tasks to call chroot(2)

Message ID

20210310181857.401675-1-mic@digikod.net (mailing list archive)

Headers

From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= <mic@digikod.net>
To: Al Viro <viro@zeniv.linux.org.uk>,
        James Morris <jmorris@namei.org>,
        Serge Hallyn <serge@hallyn.com>
Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= <mic@digikod.net>,
 Andy Lutomirski <luto@amacapital.net>,
 Casey Schaufler <casey@schaufler-ca.com>,
 Christian Brauner <christian.brauner@ubuntu.com>,
 Christoph Hellwig <hch@lst.de>, David Howells <dhowells@redhat.com>,
 Dominik Brodowski <linux@dominikbrodowski.net>,
 "Eric W . Biederman" <ebiederm@xmission.com>,
 John Johansen <john.johansen@canonical.com>,
 Kees Cook <keescook@chromium.org>, Kentaro Takeda <takedakn@nttdata.co.jp>,
 Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
 kernel-hardening@lists.openwall.com, linux-fsdevel@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org
Subject: [PATCH v2 0/1] Unprivileged chroot
Date: Wed, 10 Mar 2021 19:18:56 +0100
Message-Id: <20210310181857.401675-1-mic@digikod.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

Unprivileged chroot | expand

Message

Mickaël Salaün March 10, 2021, 6:18 p.m. UTC

Hi,

This second patch replaces the custom is_path_beneath() with the
existing path_is_under().

The chroot system call is currently limited to be used by processes with
the CAP_SYS_CHROOT capability.  This protects against malicious
procesess willing to trick SUID-like binaries.  The following patch
allows unprivileged users to safely use chroot(2).

This patch is a follow-up of a previous one sent by Andy Lutomirski some
time ago:
https://lore.kernel.org/lkml/0e2f0f54e19bff53a3739ecfddb4ffa9a6dbde4d.1327858005.git.luto@amacapital.net/

This patch can be applied on top of v5.12-rc2 .  I would really
appreciate constructive reviews.

Previous version:
https://lore.kernel.org/r/20210310161000.382796-1-mic@digikod.net

Regards,

Mickaël Salaün (1):
  fs: Allow no_new_privs tasks to call chroot(2)

 fs/open.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)


base-commit: a38fd8748464831584a19438cbb3082b5a2dab15