Re: ps under FreeBSD

["Crist J. Clark" <crist.clark () attbi com>]

On Sun, May 19, 2002 at 11:53:07AM +0200, Guillaume PELAT wrote:
> On Saturday 18 May 2002 18:57, Jakub Filonik wrote:
> > Hi,
> > I was playing with ps on FreeBSD with kern.ps_showallprocs=0 and I was
> > surprised when I have seen that I may see info about running process, if I
> > know it's ID
>
> After some investigation, the problem seems to be in sysctl_kern_proc
> function in /sys/kern/kern_proc.c
>
> The following patch seems to fix the problem(for freebsd 4.5):
>
> diff -dru sys/kern/kern_proc.c sys.new/kern/kern_proc.c
> --- sys/kern/kern_proc.c      Tue May  1 15:39:06 2001
> +++ sys.new/kern/kern_proc.c  Sat May 18 15:27:57 2002
> @@ -453,6 +453,8 @@
>                       return (0);
>               if (!PRISON_CHECK(curproc, p))
>                       return (0);
> +             if ((!ps_showallprocs) && p_trespass(curproc, p))
> +                     return (0);
>               error = sysctl_out_proc(p, req, 0);
>               return (error);
>       }

*GACK!!!*

No, no. You just made it possible for a jailed process to see
processes outside of the jail(8). ITYM,

Index: src/sys/kern/kern_proc.c
===================================================================
RCS file: /export/freebsd/ncvs/src/sys/kern/kern_proc.c,v
retrieving revision 1.63.2.8
diff -u -r1.63.2.8 kern_proc.c
--- src/sys/kern/kern_proc.c    1 May 2001 13:39:06 -0000       1.63.2.8
+++ src/sys/kern/kern_proc.c    20 May 2002 07:36:15 -0000
@@ -451,7 +451,8 @@
                p = pfind((pid_t)name[0]);
                if (!p)
                        return (0);
-               if (!PRISON_CHECK(curproc, p))
+               if (!PRISON_CHECK(curproc, p) || 
+                   (!ps_showallprocs) && p_trespass(curproc, p))
                        return (0);
                error = sysctl_out_proc(p, req, 0);
                return (error);

-- 
Crist J. Clark                     |     cjclark () alum mit edu
                                   |     cjclark () jhu edu
http://people.freebsd.org/~cjc/    |     cjc () freebsd org