From: Seth Jennings <sjenning@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Jiri Kosina <jkosina@suse.cz>, Vojtech Pavlik <vojtech@suse.cz>,
Steven Rostedt <rostedt@goodmis.org>,
live-patching@vger.kernel.org, kpatch@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] kernel: add support for live patching
Date: Fri, 7 Nov 2014 13:42:14 -0600 [thread overview]
Message-ID: <20141107194214.GE2057@cerebellum.variantweb.net> (raw)
In-Reply-To: <545D2036.9080205@amacapital.net>
On Fri, Nov 07, 2014 at 11:40:38AM -0800, Andy Lutomirski wrote:
> On 11/06/2014 06:39 AM, Seth Jennings wrote:
> > This commit introduces code for the live patching core. It implements
> > an ftrace-based mechanism and kernel interface for doing live patching
> > of kernel and kernel module functions.
> >
> > It represents the greatest common functionality set between kpatch and
> > kgraft and can accept patches built using either method.
> >
> > This first version does not implement any consistency mechanism that
> > ensures that old and new code do not run together. In practice, ~90% of
> > CVEs are safe to apply in this way, since they simply add a conditional
> > check. However, any function change that can not execute safely with
> > the old version of the function can _not_ be safely applied in this
> > version.
> >
>
> [...]
>
> > +/********************************************
> > + * Sysfs Interface
> > + *******************************************/
> > +/*
> > + * /sys/kernel/livepatch
> > + * /sys/kernel/livepatch/<patch>
> > + * /sys/kernel/livepatch/<patch>/enabled
> > + * /sys/kernel/livepatch/<patch>/<object>
> > + * /sys/kernel/livepatch/<patch>/<object>/<func>
> > + * /sys/kernel/livepatch/<patch>/<object>/<func>/new_addr
> > + * /sys/kernel/livepatch/<patch>/<object>/<func>/old_addr
> > + */
>
> Letting anyone read new_addr and old_addr is a kASLR leak, and I would
> argue that showing this information to non-root at all is probably a bad
> idea.
>
> Can you make new_addr and old_addr have mode 0600 and
> /sys/kernel/livepatch itself have mode 0500? For the latter, an admin
> who wants unprivileged users to be able to see it can easily chmod it.
Good call. Will do.
Thanks,
Seth
>
> --Andy
> --
> To unsubscribe from this list: send the line "unsubscribe live-patching" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2014-11-07 19:42 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-06 14:39 [PATCH 0/2] Kernel Live Patching Seth Jennings
2014-11-06 14:39 ` [PATCH 1/2] kernel: add TAINT_LIVEPATCH Seth Jennings
2014-11-09 20:19 ` Greg KH
2014-11-11 14:54 ` Seth Jennings
2014-11-06 14:39 ` [PATCH 2/2] kernel: add support for live patching Seth Jennings
2014-11-06 15:11 ` Jiri Kosina
2014-11-06 16:20 ` Seth Jennings
2014-11-06 16:32 ` Josh Poimboeuf
2014-11-06 18:00 ` Vojtech Pavlik
2014-11-06 22:20 ` Jiri Kosina
2014-11-07 12:50 ` Josh Poimboeuf
2014-11-07 13:13 ` Jiri Kosina
2014-11-07 13:22 ` Josh Poimboeuf
2014-11-07 14:57 ` Seth Jennings
2014-11-06 15:51 ` Jiri Slaby
2014-11-06 16:57 ` Seth Jennings
2014-11-06 17:12 ` Josh Poimboeuf
2014-11-07 18:21 ` Petr Mladek
2014-11-07 20:31 ` Josh Poimboeuf
2014-11-30 12:23 ` Pavel Machek
2014-12-01 16:49 ` Seth Jennings
2014-11-06 20:02 ` Steven Rostedt
2014-11-06 20:19 ` Seth Jennings
2014-11-07 17:13 ` module notifier: was " Petr Mladek
2014-11-07 18:07 ` Seth Jennings
2014-11-07 18:40 ` Petr Mladek
2014-11-07 18:55 ` Seth Jennings
2014-11-11 19:40 ` Seth Jennings
2014-11-11 22:17 ` Jiri Kosina
2014-11-11 22:48 ` Seth Jennings
2014-11-07 17:39 ` more patches for the same func: " Petr Mladek
2014-11-07 21:54 ` Josh Poimboeuf
2014-11-07 19:40 ` Andy Lutomirski
2014-11-07 19:42 ` Seth Jennings [this message]
2014-11-07 19:52 ` Seth Jennings
2014-11-10 10:08 ` Jiri Kosina
2014-11-10 17:31 ` Josh Poimboeuf
2014-11-13 10:16 ` Miroslav Benes
2014-11-13 14:38 ` Josh Poimboeuf
2014-11-13 17:12 ` Seth Jennings
2014-11-14 13:30 ` Miroslav Benes
2014-11-14 14:52 ` Petr Mladek
2014-11-06 18:44 ` [PATCH 0/2] Kernel Live Patching Christoph Hellwig
2014-11-06 18:51 ` Vojtech Pavlik
2014-11-06 18:58 ` Christoph Hellwig
2014-11-06 19:34 ` Josh Poimboeuf
2014-11-06 19:49 ` Steven Rostedt
2014-11-06 20:02 ` Josh Poimboeuf
2014-11-07 7:46 ` Christoph Hellwig
2014-11-07 7:45 ` Christoph Hellwig
2014-11-06 20:24 ` Vojtech Pavlik
2014-11-07 7:47 ` Christoph Hellwig
2014-11-07 13:11 ` Josh Poimboeuf
2014-11-07 14:04 ` Vojtech Pavlik
2014-11-07 15:45 ` Josh Poimboeuf
2014-11-07 21:27 ` Vojtech Pavlik
2014-11-08 3:45 ` Josh Poimboeuf
2014-11-08 8:07 ` Vojtech Pavlik
2014-11-10 17:09 ` Josh Poimboeuf
2014-11-11 9:05 ` Vojtech Pavlik
2014-11-11 17:45 ` Josh Poimboeuf
2014-11-11 1:24 ` Masami Hiramatsu
2014-11-11 10:26 ` Vojtech Pavlik
2014-11-12 17:33 ` Masami Hiramatsu
2014-11-12 21:47 ` Vojtech Pavlik
2014-11-13 15:56 ` Masami Hiramatsu
2014-11-13 16:38 ` Vojtech Pavlik
2014-11-18 12:47 ` Petr Mladek
2014-11-18 18:58 ` Josh Poimboeuf
2014-11-07 12:31 ` Josh Poimboeuf
2014-11-07 12:48 ` Vojtech Pavlik
2014-11-07 13:06 ` Josh Poimboeuf
2014-11-09 20:16 ` Greg KH
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