From: Ian Kent <raven@themaw.net>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Aleksa Sarai <cyphar@cyphar.com>,
David Howells <dhowells@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
stable <stable@vger.kernel.org>,
Christian Brauner <christian.brauner@ubuntu.com>,
Serge Hallyn <serge@hallyn.com>,
dev@opencontainers.org,
Linux Containers <containers@lists.linux-foundation.org>,
Linux API <linux-api@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC 0/1] mount: universally disallow mounting over symlinks
Date: Tue, 14 Jan 2020 13:01:28 +0800 [thread overview]
Message-ID: <d6cad1552171da1eb38c55d1d7b1ff45902b101f.camel@themaw.net> (raw)
In-Reply-To: <20200114043924.GV8904@ZenIV.linux.org.uk>
On Tue, 2020-01-14 at 04:39 +0000, Al Viro wrote:
> On Tue, Jan 14, 2020 at 08:25:19AM +0800, Ian Kent wrote:
>
> > This isn't right.
> >
> > There's actually nothing stopping a user from using a direct map
> > entry that's a multi-mount without an actual mount at its root.
> > So there could be directories created under these, it's just not
> > usually done.
> >
> > I'm pretty sure I don't check and disallow this.
>
> IDGI... How the hell will that work in v5? Who will set _any_
> traps outside the one in root in that scenario? autofs_lookup()
> won't (there it's conditional upon indirect mount). Neither
> will autofs_dir_mkdir() (conditional upon version being less
> than 5). Who will, then?
>
> Confused...
It's easy to miss.
For autofs type direct and offset mounts the flags are set at fill
super time.
They have to be set then because they are direct mounts and offset
mounts behave the same as direct mounts so they need to be set then
too. So, like direct mounts, offset mounts are each distinct autofs
(trigger) mounts.
I could check for this construct and refuse it if that's really
needed. I'm pretty sure this map construct isn't much used by
people using direct mounts.
Ian
next prev parent reply other threads:[~2020-01-14 5:01 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-30 5:20 [PATCH RFC 0/1] mount: universally disallow mounting over symlinks Aleksa Sarai
2019-12-30 5:20 ` [PATCH RFC 1/1] " Aleksa Sarai
2019-12-30 7:34 ` Linus Torvalds
2019-12-30 8:28 ` Aleksa Sarai
2020-01-08 4:39 ` Andy Lutomirski
2019-12-30 5:44 ` [PATCH RFC 0/1] " Al Viro
2019-12-30 5:49 ` Aleksa Sarai
2019-12-30 7:29 ` Aleksa Sarai
2019-12-30 7:53 ` Linus Torvalds
2019-12-30 8:32 ` Aleksa Sarai
2020-01-02 8:58 ` David Laight
2020-01-02 9:09 ` Aleksa Sarai
2020-01-01 0:43 ` Al Viro
2020-01-01 0:54 ` Al Viro
2020-01-01 3:08 ` Al Viro
2020-01-01 14:44 ` Aleksa Sarai
2020-01-01 23:40 ` Al Viro
2020-01-02 3:59 ` Aleksa Sarai
2020-01-03 1:49 ` Al Viro
2020-01-04 4:46 ` Ian Kent
2020-01-08 3:13 ` Al Viro
2020-01-08 3:54 ` Linus Torvalds
2020-01-08 21:34 ` Al Viro
2020-01-10 0:08 ` Linus Torvalds
2020-01-10 4:15 ` Al Viro
2020-01-10 5:03 ` Linus Torvalds
2020-01-10 6:20 ` Ian Kent
2020-01-12 21:33 ` Al Viro
2020-01-13 2:59 ` Ian Kent
2020-01-14 0:25 ` Ian Kent
2020-01-14 4:39 ` Al Viro
2020-01-14 5:01 ` Ian Kent [this message]
2020-01-14 5:59 ` Ian Kent
2020-01-10 21:07 ` Aleksa Sarai
2020-01-14 4:57 ` Al Viro
2020-01-14 5:12 ` Al Viro
2020-01-14 20:01 ` Aleksa Sarai
2020-01-15 14:25 ` Al Viro
2020-01-15 14:29 ` Aleksa Sarai
2020-01-15 14:34 ` Aleksa Sarai
2020-01-15 14:48 ` Al Viro
2020-01-15 13:57 ` Aleksa Sarai
2020-01-19 3:14 ` [RFC][PATCHSET][CFT] pathwalk cleanups and fixes Al Viro
2020-01-19 14:33 ` Ian Kent
2020-01-10 23:19 ` [PATCH RFC 0/1] mount: universally disallow mounting over symlinks Al Viro
2020-01-13 1:48 ` Ian Kent
2020-01-13 3:54 ` Al Viro
2020-01-13 6:00 ` Ian Kent
2020-01-13 6:03 ` Ian Kent
2020-01-13 13:30 ` Al Viro
2020-01-14 7:25 ` Ian Kent
2020-01-14 12:17 ` Ian Kent
2020-01-04 5:52 ` Andy Lutomirski
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