Problem Report kern/95977 : [jail] [patch] security.jail.jailed can be too easily shown from in jail
[jail] [patch] security.jail.jailed can be too easily shown from in jail
- Confidential
- no
- Severity
- non-critical
- Priority
- low
- Responsible
- freebsd-bugs@FreeBSD.org
- State
- closed
- Class
- update
- Submitter-Id
- current-users
- Arrival-Date
- Tue Apr 18 01:30:22 GMT 2006
- Closed-Date
- Thu May 04 06:18:27 GMT 2006
- Last-Modified
- Thu May 04 06:18:27 GMT 2006
- Originator
- Cheng-Lung Sung <clsung@freebsd.org>
- Release
- FreeBSD 6.1-PRERELEASE i386
- Organization
FreeBSD @ Taiwan
- Environment
System: FreeBSD FreeBSD.csie.nctu.edu.tw 6.1-PRERELEASE FreeBSD 6.1-PRERELEASE #7: Thu Apr 13 03:20:20 CST 2006 root@FreeBSD.csie.nctu.edu.tw:/home/usr.obj/usr/src/sys/FREEBSD i386
- Description
security.jail.jailed can be too easily shown from in jail, since it gives *someone* chances to know if he is in jail or not. I think better only show jailed when the administrator decide to insecure his machines (i.e. securelevel <=0)
- How-To-Repeat
sysctl -a | grep security.jail.jailed jexec <jid> sysctl -a |grep security.jail.jailed
- Fix
--- sys/kern/kern_jail.c.orig Mon Apr 17 22:53:48 2006 +++ sys/kern/kern_jail.c Tue Apr 18 09:21:48 2006 @@ -575,7 +575,12 @@ { int error, injail; - injail = jailed(req->td->td_ucred); + /* secured (i.e. level 1, 2, 3...) system + * do not display if jailed */ + if (securelevel_gt(req->td->td_ucred, 0) != 0) + injail = 0; + else + injail = jailed(req->td->td_ucred); error = SYSCTL_OUT(req, &injail, sizeof(injail)); return (error);
- Audit-Trail
From: Maxim Konovalov <maxim@macomnet.ru> To: Cheng-Lung Sung <clsung@freebsd.org> Cc: bug-followup@freebsd.org Subject: kern/95977 Date: Thu, 4 May 2006 00:10:26 +0400 (MSD) Hello, You can't hide a lot with this patch. ps ax | grep J or proc->p_flag & P_JAILED tests inside a jail expose the same information. -- Maxim Konovalov From: Cheng-Lung Sung <clsung@FreeBSD.org> To: Maxim Konovalov <maxim@macomnet.ru> Cc: Cheng-Lung Sung <clsung@freebsd.org>, bug-followup@freebsd.org Subject: Re: kern/95977 Date: Thu, 4 May 2006 07:04:14 +0800 --J2SCkAp4GZ/dPZZf Content-Type: text/plain; charset=big5 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, I knew that. So is that reasonable to let users easily find themselves jailed or not? If yes, please just close this pr. If no, I think we can discuss more -security@. Thanks, On Thu, May 04, 2006 at 12:10:26AM +0400, Maxim Konovalov wrote: > Hello, >=20 > You can't hide a lot with this patch. ps ax | grep J or proc->p_flag > & P_JAILED tests inside a jail expose the same information. >=20 > --=20 > Maxim Konovalov --=20 Cheng-Lung Sung - clsung@ --J2SCkAp4GZ/dPZZf Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEWTbu+AeJ85Vui8ERAn5UAJ4zzO0TZ+Rg9aFLsyDXqKalR4LXRgCfUgpK ayLr0tomUhuAbR69eHMs0Fw= =G3S2 -----END PGP SIGNATURE----- --J2SCkAp4GZ/dPZZf-- From: Maxim Konovalov <maxim@macomnet.ru> To: Cheng-Lung Sung <clsung@freebsd.org> Cc: bug-followup@freebsd.org Subject: Re: kern/95977 Date: Thu, 4 May 2006 09:37:47 +0400 (MSD) [...] > Hi, > > I knew that. So is that reasonable to let users easily find > themselves jailed or not? I think yes, by design. You see, there are no reasons to hide the sysctl invented exactly for that and in the same time leave several other methods to guess about jail. Moreover, security.jail.jailed is already used by at least one startup script and allows to re-use the same code for the system and jail startup. -- Maxim Konovalov From: Cheng-Lung Sung <clsung@FreeBSD.org> To: Maxim Konovalov <maxim@macomnet.ru> Cc: Cheng-Lung Sung <clsung@freebsd.org>, bug-followup@freebsd.org Subject: Re: kern/95977 Date: Thu, 4 May 2006 13:42:31 +0800 --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=big5 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Thus please close this pr. On Thu, May 04, 2006 at 09:37:47AM +0400, Maxim Konovalov wrote: > [...] > > Hi, > > > > I knew that. So is that reasonable to let users easily find > > themselves jailed or not? >=20 > I think yes, by design. You see, there are no reasons to hide the > sysctl invented exactly for that and in the same time leave several > other methods to guess about jail. >=20 > Moreover, security.jail.jailed is already used by at least one startup > script and allows to re-use the same code for the system and jail > startup. >=20 > --=20 > Maxim Konovalov --=20 Cheng-Lung Sung - clsung@ --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEWZRH+AeJ85Vui8ERAiuzAKCAYKZq34xrmhsqHUz6kZOGgeicWQCfXwQ2 kCIISOsdVgCgAl8/FBx7ec0= =7YTI -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5-- State-Changed-From-To: open->closed State-Changed-By: maxim State-Changed-When: Thu May 4 05:54:00 UTC 2006 State-Changed-Why: There are several methods to get know about jailed environment and no much sense to hide a one of them. There is no easy way to hide the information about jail from the prisoners. http://www.freebsd.org/cgi/query-pr.cgi?pr=95977