From: David Laight <David.Laight@ACULAB.COM>
To: 'Al Viro' <viro@zeniv.linux.org.uk>
Cc: "'Eric W. Biederman'" <ebiederm@xmission.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"Serge E. Hallyn" <serge@hallyn.com>
Subject: RE: [CFT][PATCH] proc: Update /proc/net to point at the accessing threads network namespace
Date: Mon, 3 Oct 2022 09:36:46 +0000 [thread overview]
Message-ID: <592405fa149247f58d05a213b8c6f711@AcuMS.aculab.com> (raw)
In-Reply-To: <YzjJNnzRTiSpwXHV@ZenIV>
...
> * ability to chroot(2) had always been equivalent to ability to undo
> chroot(2). If you want to prevent getting out of there, you need
> (among other things) to prevent the processes to be confined from
> further chroot(2).
Not always, certainly not historically.
chroot() inside a chroot() just constrained you further.
If fchdir() and openat() have broken that it is a serious
problem.
NetBSD certainly has checks to detect (log and fix)
programs that have (or might) escape from chroots.
unshare() seems to create a 'shadow' inode structure
for the chroot's "/" so at least some of the tests
when following ".." fail to detect it.
I also thought containers relied on the same scheme?
(But I'm too old fashioned to have looked into them!)
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-10-03 9:43 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-29 15:22 [PATCH 3/4] proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net David Laight
2022-09-29 18:21 ` Linus Torvalds
2022-09-29 18:50 ` Al Viro
2022-09-29 19:00 ` Al Viro
2022-09-29 19:05 ` Linus Torvalds
2022-09-29 19:34 ` Al Viro
2022-09-29 21:13 ` Linus Torvalds
2022-09-29 21:21 ` Al Viro
2022-09-29 21:27 ` Al Viro
2022-09-29 21:31 ` Linus Torvalds
2022-09-29 21:15 ` Al Viro
2022-09-29 21:29 ` Linus Torvalds
2022-09-29 22:14 ` Eric W. Biederman
2022-09-29 22:48 ` [CFT][PATCH] proc: Update /proc/net to point at the accessing threads network namespace Eric W. Biederman
2022-09-29 23:38 ` Al Viro
2022-09-30 3:19 ` kernel test robot
2022-09-30 6:07 ` kernel test robot
2022-09-30 9:30 ` David Laight
2022-09-30 16:17 ` Eric W. Biederman
2022-09-30 21:28 ` David Laight
2022-10-01 23:11 ` Al Viro
2022-10-03 9:36 ` David Laight [this message]
2022-10-03 14:03 ` Al Viro
2022-10-03 17:07 ` Eric W. Biederman
2022-10-03 18:49 ` Al Viro
2022-10-04 8:53 ` David Laight
2022-10-05 13:10 ` [proc] 5336f1902b: BUG:KASAN:global-out-of-bounds_in_memchr kernel test robot
2022-09-29 19:00 ` [PATCH 3/4] proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2022-09-30 14:01 [CFT][PATCH] proc: Update /proc/net to point at the accessing threads network namespace Alexey Dobriyan
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