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Message-ID: <89548338-f716-c110-0f85-3ef880bbd723@schaufler-ca.com>
Date:   Tue, 30 Aug 2022 06:47:52 -0700
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Subject: Re: [PATCH v4] vfs, security: Fix automount superblock LSM init
 problem, preventing NFS sb sharing
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To:     David Howells <dhowells@redhat.com>
Cc:     Christian Brauner <brauner@kernel.org>, viro@zeniv.linux.org.uk,
        Jeff Layton <jlayton@kernel.org>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna@kernel.org>,
        Scott Mayhew <smayhew@redhat.com>,
        Paul Moore <paul@paul-moore.com>, linux-nfs@vger.kernel.org,
        selinux@vger.kernel.org, linux-security-module@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, dwysocha@redhat.com,
        linux-kernel@vger.kernel.org, casey@schaufler-ca.com
References: <c648aa7c-a49c-a7e2-6a05-d1dfe44b8fdb@schaufler-ca.com>
 <166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk>
 <20220826082439.wdestxwkeccsyqtp@wittgenstein>
 <1903709.1661849345@warthog.procyon.org.uk>
From:   Casey Schaufler <casey@schaufler-ca.com>
In-Reply-To: <1903709.1661849345@warthog.procyon.org.uk>
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On 8/30/2022 1:49 AM, David Howells wrote:
> Casey Schaufler <casey@schaufler-ca.com> wrote:
>
>> The authors of this version of the mount code failed to look
>> especially closely at how Smack maintains label names. Once a
>> label name is used in the kernel it is kept on a list forever.
>> All the copies of smk_known here and in the rest of the mount
>> infrastructure are unnecessary and wasteful. The entire set of
>> Smack hooks that deal with mounting need to be reworked to remove
>> that waste. It's on my list of Smack cleanups, but I'd be happy
>> if someone else wanted a go at it.
> I don't have time to overhaul Smack right now.  Should I drop the Smack part
> of the patch?

No. I appreciate that you're including Smack as part of the effort.
I would much rather have the code working as you have it than have
to go in later and do it all from scratch. With luck I should be able
to get someone with a considerably lower level of expertise to work
on it.

> David