From: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: "Serge E. Hallyn" <serge.hallyn@canonical.com>,
Herbert Poetzl <herbert@13thfloor.at>
Subject: 3.0: user namespace problem with capabilities
Date: Thu, 21 Jul 2011 14:22:23 +0200 [thread overview]
Message-ID: <201107211422.23861.a.miskiewicz@gmail.com> (raw)
Hi,
linux-vserver guys think that there is a problem with user namespace in
upcoming 3.0
"this is a mainline/upstream bug, which basically happens
when unsharing the USER namespace. what happens is that
all capabilities are dropped, and as result, the userspace
tool cannot issue Linux-VServer syscall commands anymore
(because of missing CAP_CONTEXT)"
"this can be verified on vanilla linux-3.0 kernels with
http://vserver.13thfloor.at/Stuff/clone_newuser.c
in the following way:
gcc -o clone_newuser clone_newuser.c
./clone_newuser ls /root/
assuming that /root does not have any right for 'other'
this will result in a permission denied (when the USER
namespace is compiled into the kernel)"
Whole post:
http://list.linux-vserver.org/archive?msp:5151:ekldgndhkgmehnehiegi
What's maintainers opinion on this?
--
Arkadiusz Miśkiewicz PLD/Linux Team
arekm / maven.pl http://ftp.pld-linux.org/
next reply other threads:[~2011-07-21 12:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-21 12:22 Arkadiusz Miskiewicz [this message]
2011-07-21 13:40 ` 3.0: user namespace problem with capabilities Serge E. Hallyn
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