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Date: Wed, 8 Nov 2023 08:58:32 +0100
From: Christian Brauner <brauner@kernel.org>
To: Miklos Szeredi <mszeredi@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
	linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
	linux-man@vger.kernel.org, linux-security-module@vger.kernel.org,
	Karel Zak <kzak@redhat.com>, Ian Kent <raven@themaw.net>,
	David Howells <dhowells@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <christian@brauner.io>,
	Amir Goldstein <amir73il@gmail.com>,
	Matthew House <mattlloydhouse@gmail.com>,
	Florian Weimer <fweimer@redhat.com>, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v4 4/6] add statmount(2) syscall
Message-ID: <20231108-zwerge-unheil-b3f48a84038d@brauner>
References: <20231025140205.3586473-5-mszeredi@redhat.com>
 <4ab327f80c4f98dffa5736a1acba3e0d.paul@paul-moore.com>
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In-Reply-To: <4ab327f80c4f98dffa5736a1acba3e0d.paul@paul-moore.com>

> > +static int do_statmount(struct stmt_state *s)
> > +{
> > +	struct statmnt *sm = &s->sm;
> > +	struct mount *m = real_mount(s->mnt);
> > +	size_t copysize = min_t(size_t, s->bufsize, sizeof(*sm));
> > +	int err;
> > +
> > +	err = security_sb_statfs(s->mnt->mnt_root);
> > +	if (err)
> > +		return err;
> > +
> > +	if (!capable(CAP_SYS_ADMIN) &&
> > +	    !is_path_reachable(m, m->mnt.mnt_root, &s->root))
> > +		return -EPERM;
> 
> In order to be consistent with our typical access control ordering,
> please move the security_sb_statfs() call down to here, after the
> capability checks.

I've moved the security_sb_statfs() calls accordingly.