Re: Wmmon under FreeBSD

[ajax () LINWORTH ORG (Ajax)]

On Tue, 21 Dec 1999, Steve Reid wrote:

> Wmmon is a popular program for monitoring CPU load and other system
> utilization. It runs as a dockapp under WindowMaker.
>
> The FreeBSD version of this program has a feature that can be trivially
> exploited to gain group kmem in recent installs, or user root in really
> old installs. This affects the FreeBSD version because under FreeBSD the
> program must be installed setgid kmem or setuid root in order to access
> system load information through the memory devices. The Linux version
> should not be vulnerable because it reads information through procfs
> which requires no special privileges.
> <snip>

An alternative solution would be to read such information from kernfs,
usually (although optionally) mounted at /kern.  kernfs is the *bsd
equivalent to many of the files in linux's /proc.  This would, of
course, require the app to be rewritten to use /kern instead of
/dev/kmem, but well worth it in my opinion.

I should like to know why more apps don't require the *bsd {proc,kern}fs
interface.  They were, after all, designed to reduce the need for read
access to /dev/kmem.

.a.j.a.x. @ vxgas.linworth.org
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