linux-ext4 - Re: [PATCH v6 39/40] xfs: support idmapped mounts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 3 Mar 2021 08:01:03 +0100
From:   Christoph Hellwig <hch@....de>
To:     "Darrick J. Wong" <djwong@...nel.org>
Cc:     Christian Brauner <christian.brauner@...ntu.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Christoph Hellwig <hch@....de>, linux-fsdevel@...r.kernel.org,
        John Johansen <john.johansen@...onical.com>,
        James Morris <jmorris@...ei.org>,
        Mimi Zohar <zohar@...ux.ibm.com>,
        Dmitry Kasatkin <dmitry.kasatkin@...il.com>,
        Stephen Smalley <stephen.smalley.work@...il.com>,
        Casey Schaufler <casey@...aufler-ca.com>,
        Arnd Bergmann <arnd@...db.de>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>,
        Geoffrey Thomas <geofft@...reload.com>,
        Mrunal Patel <mpatel@...hat.com>,
        Josh Triplett <josh@...htriplett.org>,
        Andy Lutomirski <luto@...nel.org>,
        Theodore Tso <tytso@....edu>, Alban Crequy <alban@...volk.io>,
        Tycho Andersen <tycho@...ho.ws>,
        David Howells <dhowells@...hat.com>,
        James Bottomley <James.Bottomley@...senpartnership.com>,
        Seth Forshee <seth.forshee@...onical.com>,
        Stéphane Graber <stgraber@...ntu.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Aleksa Sarai <cyphar@...har.com>,
        Lennart Poettering <lennart@...ttering.net>,
        "Eric W. Biederman" <ebiederm@...ssion.com>, smbarber@...omium.org,
        Phil Estes <estesp@...il.com>, Serge Hallyn <serge@...lyn.com>,
        Kees Cook <keescook@...omium.org>,
        Todd Kjos <tkjos@...gle.com>, Paul Moore <paul@...l-moore.com>,
        Jonathan Corbet <corbet@....net>,
        containers@...ts.linux-foundation.org,
        linux-security-module@...r.kernel.org, linux-api@...r.kernel.org,
        linux-ext4@...r.kernel.org, linux-xfs@...r.kernel.org,
        linux-integrity@...r.kernel.org, selinux@...r.kernel.org
Subject: Re: [PATCH v6 39/40] xfs: support idmapped mounts

On Mon, Mar 01, 2021 at 12:05:20PM -0800, Darrick J. Wong wrote:
> > +	if (breq->mnt_userns != &init_user_ns) {
> > +		xfs_warn_ratelimited(breq->mp,
> > +			"bulkstat not supported inside of idmapped mounts.");
> > +		return -EINVAL;
> 
> Shouldn't this be -EPERM?
> 
> Or -EOPNOTSUPP?

-EINVAL is what we return for all our nor suppored ioctls, so I think it
is the right choice here, and should generally trigger the right
fallbacks.

> Also, I'm not sure why bulkstat won't work in an idmapped mount but
> bulkstat_single does?  You can use the singleton version to stat inodes
> that aren't inside the submount.

Looking at it again I think we should fail BULKSTAT_SINGLE as well.
I had somehow assumed BULKSTAT_SINGLE would operate on the inode of
the open file, in which case it would be fine.  But it doesn't so that
argument doesn't count.