From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33E8EC433E6 for ; Wed, 10 Feb 2021 23:52:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0643864E0D for ; Wed, 10 Feb 2021 23:52:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234160AbhBJXwC (ORCPT ); Wed, 10 Feb 2021 18:52:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234133AbhBJXvu (ORCPT ); Wed, 10 Feb 2021 18:51:50 -0500 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7E46C06174A for ; Wed, 10 Feb 2021 15:51:09 -0800 (PST) Received: by mail-ej1-x636.google.com with SMTP id f14so7219174ejc.8 for ; Wed, 10 Feb 2021 15:51:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1M0KC3p1meyDQrYPzDqxypfZ2M1GwZFs8VgujKNOBPw=; b=UIZslfjRO/9DuoX7z8lTy1KL6HjZR0/5cZp7deUc8QMR5nfUEzG0dNExmyqkCF4f6y WLuSVQFYypxlJksG9emU4luaA9tYyJoc4XeLGX9vvp0DsPHPWlRAX08NmSH3Em3Npnzi i6iNNUSZb3Y+yXgHisVAAwJbuv/ojTbhWwRvsEwwHpBhA0zUx6WxjzQq0/7TJKZSE3AX 5cDtGCSGgyeevLu7cFf9ClQ+7YMuvrqDjLA48QSG9YsoX308kU025vSB2l3zBylA/QGJ 1rOrBJcb8cq9EkaHm8TzfDTNpHuTzvxKHvX//Us6R88Zkjh/sGRis+1qMIzrTukYe3p+ Wgdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1M0KC3p1meyDQrYPzDqxypfZ2M1GwZFs8VgujKNOBPw=; b=iTjHB4iOX56knIIwVEC5wNUJxGFqdiuQVj501K8kDr7i220ZMdIeSQHTY9Tk3qG2gs sr66bNwNkRnhDcXDmJ91ZThkqtiEam9EpFEF3M+/+DzivaD4xR0jF1Ia5W98LdSBCJMu GNyapGKwjm55ITqf2mdskvuyECQtkIWuMgYBCB/FGlWPmHxSW4lqZ3AAxgIEkjp2VoD/ Q1+UAQNT5fpFKR2e1M4cYx/13u3xIYqOj5npBTyFK0UG6VDUPVmHk/cK2x5z2zAZU5nV BZkQOqyzJ3ZMiK9x/tfDYsWmK1MQ/LA7HtCK7WBgWxE9THvQOdNehqCa+wimvCoh2mho WHIQ== X-Gm-Message-State: AOAM533aeB8HT7le4RqD6HmOShEB6K3P6hQZS4ku57U1ar1hxMefBaoj mS2iFNPVjB5bMUVp9rFIKAdqHVo4CFKyUK+t2BLD X-Google-Smtp-Source: ABdhPJxbvum50dPhfmLT6PkFvr4im9qOS4UUgVDGP9cifAfcGFXDb/3Tanc5Hf/SztMBKxtZQyI0XsTmkWCqIuEM5Jk= X-Received: by 2002:a17:906:8519:: with SMTP id i25mr5590393ejx.106.1613001068566; Wed, 10 Feb 2021 15:51:08 -0800 (PST) MIME-Version: 1.0 References: <20210209200233.GF3171@redhat.com> In-Reply-To: <20210209200233.GF3171@redhat.com> From: Paul Moore Date: Wed, 10 Feb 2021 18:50:57 -0500 Message-ID: Subject: Re: [PATCH] selinux: Allow context mounts for unpriviliged overlayfs To: Vivek Goyal Cc: selinux@vger.kernel.org, linux-unionfs@vger.kernel.org, Stephen Smalley , Eric Paris , Miklos Szeredi , Daniel J Walsh , Ondrej Mosnacek , Amir Goldstein , Giuseppe Scrivano Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Tue, Feb 9, 2021 at 3:02 PM Vivek Goyal 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 > Signed-off-by: Vivek Goyal > --- > 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