linux-kernel - Re: [PATCH 1/2] autofs4: allow autofs to work outside the initial PID namespace

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:	Mon, 26 Nov 2012 09:05:46 +0100
From:	Miklos Szeredi <miklos@...redi.hu>
To:	Ian Kent <raven@...maw.net>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	autofs@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, sukadev@...ux.vnet.ibm.com,
	serge.hallyn@...onical.com, Al Viro <viro@...iv.linux.org.uk>
Subject: Re: [PATCH 1/2] autofs4: allow autofs to work outside the initial PID namespace

On Mon, Nov 26, 2012 at 3:29 AM, Ian Kent <raven@...maw.net> wrote:
>> > > MS_UNBINDABLE says:  skip this mount when copying a mount tree, such
>> > > as when the mount namespace is cloned.
>> > >
>> > > If you set MS_UNBINDABLE on autofs mounts then they will simply not
>> > > appear in a cloned namespace.  Which sounds like a good idea,  no?
>> >
>> > Good point.  If the desire is for a mount to be managed by autofs
>> > setting MS_UNBINDABLE seems required.
>>
>> Arrgh, I know that's something I should have looked into long ago.
>> The fact is that autofs mounts are directly related to a specific path
>> defined by automount maps that are associated with the daemon so bind
>> mounting them elsewhere makes no sense.
>
> Except, AFAICS, they do appear in the clone.

Hmm, yes, apparently the semantics of MS_UNBINDABLE only apply to
actual bind mounts not to namespace cloning. Even though the two
operations are closely related.  Not sure why this is so, but it is
probably not a good idea to change the semantics at this point.

Thanks,
Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/