linux-kernel - Re: [PATCH] userns/capability: Add user namespace capability

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 17 Oct 2015 22:17:36 +0200
From:	Richard Weinberger <richard.weinberger@...il.com>
To:	Tobias Markus <tobias@...lix.eu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Al Viro <viro@...iv.linux.org.uk>,
	Serge Hallyn <serge.hallyn@...onical.com>,
	Andrew Morton <akpm@...uxfoundation.org>,
	Andy Lutomirski <luto@...capital.net>,
	Christoph Lameter <cl@...ux.com>,
	"Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>,
	LSM <linux-security-module@...r.kernel.org>,
	"open list:ABI/API" <linux-api@...r.kernel.org>,
	linux-man <linux-man@...r.kernel.org>
Subject: Re: [PATCH] userns/capability: Add user namespace capability

On Sat, Oct 17, 2015 at 5:58 PM, Tobias Markus <tobias@...lix.eu> wrote:
> One question remains though: Does this break userspace executables that
> expect being able to create user namespaces without priviledge? Since
> creating user namespaces without CAP_SYS_ADMIN was not possible before
> Linux 3.8, programs should already expect a potential EPERM upon calling
> clone. Since creating a user namespace without CAP_SYS_USER_NS would
> also cause EPERM, we should be on the safe side.

In case of doubt, yes it will break existing software.
Hiding user namespaces behind CAP_SYS_USER_NS will not magically
make them secure.

-- 
Thanks,
//richard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/