Re: [RFC PATCH 1/3] cgroup: fix parsing empty mount option string

From: Ondrej Mosnacek <omosnace@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
	cgroups@vger.kernel.org, Stephen Smalley <sds@tycho.nsa.gov>,
	Li Zefan <lizefan@huawei.com>,
	Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [RFC PATCH 1/3] cgroup: fix parsing empty mount option string
Date: Fri, 28 Dec 2018 16:14:01 +0100	[thread overview]
Message-ID: <CAFqZXNs+Zi0-6Syj9Uy4TajOQkukngafyUp_VW+VStzgorVYOw@mail.gmail.com> (raw)
In-Reply-To: <20181213160309.GT2509588@devbig004.ftw2.facebook.com>

Hi Tejun,

On Thu, Dec 13, 2018 at 5:03 PM Tejun Heo <tj@kernel.org> wrote:
>
> Hello,
>
> On Thu, Dec 13, 2018 at 03:17:37PM +0100, Ondrej Mosnacek wrote:
> > This fixes the case where all mount options specified are consumed by an
> > LSM and all that's left is an empty string. In this case cgroupfs should
> > accept the string and not fail.
> >
> > How to reproduce (with SELinux enabled):
> >
> >     # umount /sys/fs/cgroup/unified
> >     # mount -o context=system_u:object_r:cgroup_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified
> >     mount: /sys/fs/cgroup/unified: wrong fs type, bad option, bad superblock on cgroup2, missing codepage or helper program, or other error.
> >     # dmesg | tail -n 1
> >     [   31.575952] cgroup: cgroup2: unknown option ""
> >
> > Fixes: 67e9c74b8a87 ("cgroup: replace __DEVEL__sane_behavior with cgroup2 fs type")
> > [NOTE: should apply on top of commit 5136f6365ce3 ("cgroup: implement "nsdelegate" mount option"), older versions need manual rebase]
> > Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
> > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
>
> Applied to cgroup/for-4.21.

I still can't see the patch in your for-4.21 branch [1] (and it
doesn't seem to be included in your 4.21-rc1 pull request either [2]).
Did you perhaps forget to apply it?

[1] https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/log/?h=for-4.21
[2] https://lore.kernel.org/lkml/20181228021605.GI2509588@devbig004.ftw2.facebook.com/

Cheers,

--
Ondrej Mosnacek <omosnace at redhat dot com>
Associate Software Engineer, Security Technologies
Red Hat, Inc.