From: Paul Moore <paul@paul-moore.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: selinux@vger.kernel.org, linux-unionfs@vger.kernel.org,
Stephen Smalley <stephen.smalley.work@gmail.com>,
Eric Paris <eparis@parisplace.org>,
Miklos Szeredi <miklos@szeredi.hu>,
Daniel J Walsh <dwalsh@redhat.com>,
Ondrej Mosnacek <omosnace@redhat.com>,
Amir Goldstein <amir73il@gmail.com>,
Giuseppe Scrivano <gscrivan@redhat.com>
Subject: Re: [PATCH] selinux: Allow context mounts for unpriviliged overlayfs
Date: Wed, 10 Feb 2021 18:50:57 -0500 [thread overview]
Message-ID: <CAHC9VhQYE3ga53AiK2r-568_=2U0BJe+L4g9U_J0dLinzJqXYA@mail.gmail.com> (raw)
In-Reply-To: <20210209200233.GF3171@redhat.com>
On Tue, Feb 9, 2021 at 3:02 PM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> Now overlayfs allow unpriviliged mounts. That is root inside a non-init
> user namespace can mount overlayfs. This was added in 5.10 kernel.
>
> Giuseppe tried to mount overlayfs with option "context" and it failed
> with error -EACCESS.
>
> $ su test
> $ unshare -rm
> $ mkdir -p lower upper work merged
> $ mount -t overlay -o lowerdir=lower,workdir=work,upperdir=upper,userxattr,context='system_u:object_r:container_file_t:s0' none merged
>
> This fails with -EACCESS. It works if option "-o context" is not specified.
>
> Little debugging showed that selinux_set_mnt_opts() returns -EACCESS.
>
> So this patch adds "overlay" to the list, where it is fine to specific
> context from non init_user_ns.
>
> Reported-by: Giuseppe Scrivano <gscrivan@redhat.com>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> ---
> security/selinux/hooks.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
This seems reasonable, but since we are at -rc7 this week it will need
to wait until after the upcoming merge window. It's too late in the
cycle for new features.
--
paul moore
www.paul-moore.com
next prev parent reply other threads:[~2021-02-10 23:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 20:02 [PATCH] selinux: Allow context mounts for unpriviliged overlayfs Vivek Goyal
2021-02-10 23:50 ` Paul Moore [this message]
2021-02-11 14:01 ` Vivek Goyal
2021-02-11 16:32 ` Paul Moore
2021-02-11 16:56 ` Vivek Goyal
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