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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andy Lutomirski <luto@kernel.org>
Cc: Jann Horn <jannh@google.com>,
	Linux API <linux-api@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: new ...at() flag: AT_NO_JUMPS
Date: Fri, 5 May 2017 02:06:54 +0100	[thread overview]
Message-ID: <20170505010654.GN29622@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CALCETrXE2-841_VRgDJxRZBYAfvSe+GQN+0Jkfh3k1pL8XfDaA@mail.gmail.com>

On Thu, May 04, 2017 at 05:44:19PM -0700, Andy Lutomirski wrote:
> > It's not quite O_BENEATH, and IMO it's saner that way - a/b/c/../d is
> > bloody well allowed, and so are relative symlinks that do not lead out of
> > the subtree.  If somebody has a good argument in favour of flat-out
> > ban on .. (_other_ than "other guys do it that way, and it doesn't need
> > to make sense 'cuz security!!1!!!", please), I'd be glad to hear it.
> 
> I don't have an argument for allowing '..'.  I think it would be okay
> to disallow it, but I don't think it matters all that much either way.

Relative symlinks as argument in favour of allowing .. _when_ _it_ _stays_
_in_ _subtree_.

> > For the latter I would prefer -EXDEV, for obvious reasons.  For the former...
> > not sure.  I'm not too happy about -ELOOP, but -EPERM (as with O_BENEATH)
> > is an atrocity - it's even more overloaded.
> >
> > Suggestions?
> 
> -EDOTDOT would be amusing.

For ln -s /tmp foo/bar, lookup for foo/bar/baz?  Seriously?  Hell, even
-EXDEV would make more sense...

  reply	other threads:[~2017-05-05  1:06 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-29 22:04 Al Viro
2017-04-29 23:17 ` Andy Lutomirski
2017-04-29 23:25   ` Al Viro
2017-04-30  1:13     ` Andy Lutomirski
2017-04-30  4:38     ` Matthew Wilcox
2017-04-30 16:10       ` Al Viro
2017-05-01  4:52         ` Andy Lutomirski
2017-05-01  5:15           ` Al Viro
2017-05-01 17:36 ` Jann Horn
2017-05-01 19:37   ` Andy Lutomirski
2017-05-05  0:30   ` Al Viro
2017-05-05  0:44     ` Andy Lutomirski
2017-05-05  1:06       ` Al Viro [this message]
2017-05-05  1:27     ` Linus Torvalds
2017-05-05  3:00       ` Al Viro
2017-05-05  4:01         ` Linus Torvalds
2017-05-05  4:31           ` Andy Lutomirski
2017-05-05  2:47     ` Jann Horn
2017-05-05  3:46       ` Linus Torvalds
2017-05-05  4:39         ` Al Viro
2017-05-05  4:44           ` Andy Lutomirski
2017-05-05 20:04             ` Eric W. Biederman
2017-05-05 20:28           ` Eric W. Biederman
2017-05-08 19:34             ` Mickaël Salaün
2017-05-18  8:50     ` David Drysdale
2017-09-10 20:26 Jürg Billeter

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