[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 20 Apr 2012 09:32:19 -0600
From: Kurt Seifried <kseifried@...hat.com>
To: Marcus Meissner <meissner@...e.de>
CC: oss-security@...ts.openwall.com, security@...nel.org
Subject: Re: CVE request: pid namespace leak in kernel 3.0
and 3.1
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 04/20/2012 01:05 AM, Marcus Meissner wrote:
> On Thu, Apr 19, 2012 at 09:09:55PM -0600, Kurt Seifried wrote:
>> On 04/19/2012 03:48 PM, Marcus Meissner wrote:
>>> Hi,
>>>
>>> we had a user, Vadim Ponomarev (ccrssaa at karelia.ru), report
>>> a pid namespace leak caused by vsftpd.
>>>
>>> https://bugzilla.novell.com/show_bug.cgi?id=757783
>>>
>>> He provided a simple reproducer:
>>>
>>> #include <stdio.h> #include <errno.h> #include <signal.h>
>>> #include <sched.h> #include <linux/sched.h> #include <unistd.h>
>>> #include <sys/syscall.h>
>>>
>>> int main(int argc, char *argv[]) { int i, ret;
>>>
>>> for (i = 0; i < 10000; i++) {
>>>
>>> if (0 == (ret = syscall(__NR_clone, CLONE_NEWPID | CLONE_NEWIPC
>>> | CLONE_NEWNET | SIGCHLD, NULL))) return 0;
>>>
>>> if (-1 == ret) { perror("clone"); break; }
>>>
>>> } return 0; }
>>>
>>>
>>> and checking "cat /proc/slabinfo|grep pid_namespace" gives
>>> 10000 more active slots after running it on 3.0.13 (+SUSE
>>> patches) and 3.1.10 (+SUSE patches).
>>>
>>>
>>> Running this on 3.2.0 (+SUSE Patches) did not result in more
>>> slots, so it was probably fixed between 3.1 and 3.2 (but
>>> someone else cross check perhaps).
>>>
>>> Any idea welcome on which patch fixed this, I tried
>>> 1b26c9b334044cff6d1d2698f2be41bc7d9a0864 but it seems not
>>> helping.
>>>
>>> Ciao, Marcus
>>
>> Can this be triggered by a non privileged user/process? Eugene
>> mentions that CAP_SYS_ADMIN seems to be required, if so it seems
>> like there isn't much of a trust boundary violation going on
>> (anyone/thing with CAP_SYS_ADMIN is already in pretty good).
>
> The above code ... no.
>
> However, vsftpd has this code pattern in its newer namespace
> enabled versions.
>
> So it can be triggered via a namespace enabled vsftpd remotely, by
> just running wget on even anonymous areas in a loop.
Ok that seems like a reasonably sane use case (e.g. as opposed to
granting a local program CAP_SYS_ADMIN). Please use CVE-2012-2127 for
this issue.
> Ciao, Macus
- --
Kurt Seifried Red Hat Security Response Team (SRT)
PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/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=GZlG
-----END PGP SIGNATURE-----
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
