linux-kernel - Re: [RFC] Tracepoint proposal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <y0mtzfjavyq.fsf@ton.toronto.redhat.com>
Date:	Tue, 24 Jun 2008 07:55:25 -0400
From:	fche@...hat.com (Frank Ch. Eigler)
To:	"Takashi Nishiie" <t-nishiie@...css.fujitsu.com>
Cc:	"'Masami Hiramatsu'" <mhiramat@...hat.com>,
	"'Alexey Dobriyan'" <adobriyan@...il.com>,
	"'Mathieu Desnoyers'" <mathieu.desnoyers@...ymtl.ca>,
	"'Peter Zijlstra'" <peterz@...radead.org>,
	"'Steven Rostedt'" <rostedt@...dmis.org>,
	"'Ingo Molnar'" <mingo@...e.hu>,
	"'LKML'" <linux-kernel@...r.kernel.org>,
	"'systemtap-ml'" <systemtap@...rces.redhat.com>,
	"'Hideo AOKI'" <haoki@...hat.com>
Subject: Re: [RFC] Tracepoint proposal

"Takashi Nishiie" <t-nishiie@...css.fujitsu.com> writes:

> [...]
> Each kernel sub-system seems to have its own way of dealing with 
> debugging statements. Some of these methods include 'dprintk', 
> 'pr_debug', 'dev_debug', 'DEBUGP'. I think that these functions are
> the tracepoints that has been availably mounted without setting up 
> the tool set of the outside. I think whether mounting that unites 
> these functions can be done if kernel marker and tracepoint are used.

There are efforts underway to collect these various debug methods into
a single run-time-dynamic stream, which may even turn out to connect
to markers.

> By the way, isn't there problem on security?  What kprobe, jprobe,
> and kernel marker, etc. offer looks like what the framework of Linux
> Security Module had offered before.  Gotten kprobe, jprobe, and
> kernel marker, etc. should not be exported to the userland for
> security because it becomes the hotbed of rootkits.

These are all kernel-side facilities with no direct connection to
user-land.

> Users such as kprobe, jprobe, and kernel marker should not be
> Loadable Kernel Module. [...]

That would defeat their usefulness.  Remember, kernel modules run with
no hardware-level restrictions at all, so if an adversary managed to
load up some kernel malware module, the game is over, whether or not
they use kprobes.

- FChE
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/