linux-kernel - Re: WMI and Kernel:User interface

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: <20170613160547.GA25404@kroah.com>
Date:   Tue, 13 Jun 2017 18:05:47 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Darren Hart <dvhart@...radead.org>
Cc:     Pali Rohár <pali.rohar@...il.com>,
        Christoph Hellwig <hch@...radead.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Mario Limonciello <mario_limonciello@...l.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rafael Wysocki <rjw@...ysocki.net>,
        Andy Lutomirski <luto@...capital.net>,
        LKML <linux-kernel@...r.kernel.org>,
        platform-driver-x86@...r.kernel.org
Subject: Re: WMI and Kernel:User interface

On Tue, Jun 13, 2017 at 08:44:19AM -0700, Darren Hart wrote:
> > In some cases filter function can be simple in some cases hard. I can
> > image that usage of while listing, plus in some cases also filtering
> > (when it would be relatively easy to implement).
> 
> See my response to Christoph - to address the concern of breaking userspace
> later, if we consider this a proxy instead of a filter, we can make it
> transparent to userspace and maintain kernel driver state. The driver can
> register a wmi_method_proxy callback which can choose to proxy the method call
> or not. If it does, it can update it's own state and perform the requested
> action through it's own infrastructure, populate the out buffer and send it back
> up to userspace. I would hope to see as few of these as possible, but they would
> allow for protecting the kernel drivers while still enabling userspace usage of
> WMI.

Ok, I think we need to see some real code here to get any further with
this.  There's a reason we don't do big design discussions without
patches, as that usually answers all of the questions involved.

Please, let's see some code before anything else.

thanks,

greg k-h