Received-SPF: pass (google.com: domain of linux-kernel+bounces-184106-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Feedback-ID: i76614979:Fastmail
Date: Mon, 20 May 2024 12:25:27 -0700
From: Jonathan Calmels <jcalmels@3xx0.net>
To: Tycho Andersen <tycho@tycho.pizza>
Cc: brauner@kernel.org, ebiederm@xmission.com, 
	Luis Chamberlain <mcgrof@kernel.org>, Kees Cook <keescook@chromium.org>, 
	Joel Granados <j.granados@samsung.com>, Serge Hallyn <serge@hallyn.com>, 
	Paul Moore <paul@paul-moore.com>, James Morris <jmorris@namei.org>, 
	David Howells <dhowells@redhat.com>, Jarkko Sakkinen <jarkko@kernel.org>, containers@lists.linux.dev, 
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, 
	linux-security-module@vger.kernel.org, keyrings@vger.kernel.org
Subject: Re: [PATCH 3/3] capabilities: add cap userns sysctl mask
Message-ID: <ptixqmplbovxmqy3obybwphsie2xaybfj46xyafdnol7bme4z4@4kwdljmrkdpn>
References: <20240516092213.6799-1-jcalmels@3xx0.net>
 <20240516092213.6799-4-jcalmels@3xx0.net>
 <ZktQZi5iCwxcU0qs@tycho.pizza>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <ZktQZi5iCwxcU0qs@tycho.pizza>

On Mon, May 20, 2024 at 07:30:14AM GMT, Tycho Andersen wrote:
> there is an ongoing effort (started at [0]) to constify the first arg
> here, since you're not supposed to write to it. Your usage looks
> correct to me, so I think all it needs is a literal "const" here.

Will do, along with the suggestions from Jarkko

> > +	struct ctl_table t;
> > +	unsigned long mask_array[2];
> > +	kernel_cap_t new_mask, *mask;
> > +	int err;
> > +
> > +	if (write && (!capable(CAP_SETPCAP) ||
> > +		      !capable(CAP_SYS_ADMIN)))
> > +		return -EPERM;
> 
> ...why CAP_SYS_ADMIN? You mention it in the changelog, but don't
> explain why.

No reason really, I was hoping we could decide what we want here.
UMH uses CAP_SYS_MODULE, Serge mentioned adding a new cap maybe.