kern/95977:

[Cheng-Lung Sung]

>Number:         95977
>Category:       kern
>Synopsis:       
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          update
>Submitter-Id:   current-users
>Arrival-Date:   Tue Apr 18 01:30:22 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Cheng-Lung Sung
>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 at 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);
>Release-Note:
>Audit-Trail:
>Unformatted: