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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Aleksa Sarai' <cyphar@cyphar.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
CC:     Al Viro <viro@zeniv.linux.org.uk>,
        David Howells <dhowells@redhat.com>,
        Eric Biederman <ebiederm@xmission.com>,
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        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
Thread-Topic: [PATCH RFC 0/1] mount: universally disallow mounting over
 symlinks
Thread-Index: AQHVvuu3ha8TNgK7w0ufQ/mBgQviWKfXFrEg
Date:   Thu, 2 Jan 2020 08:58:09 +0000
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From: Aleksa Sarai
> Sent: 30 December 2019 08:32
...
> I'm not sure I agree -- as I mentioned in my other mail, re-opening
> through /proc/self/fd/$n works *very* well and has for a long time (in
> fact, both LXC and runc depend on this working).

I thought it was marginally broken because it is followed as a symlink?
On, for example, NetBSD /proc/<n>/fd/<n> is a real reference to the
filesystem inode and can be used to link the file back into the filesystem
if all the directory entries have been removed.

	David

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