lkml.org 
[lkml]   [2016]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRE: [PATCH] printk: introduce kptr_restrict level 3
    Date
    > -----Original Message-----
    > From: Christoph Hellwig [mailto:hch@infradead.org]
    > Sent: Thursday, October 6, 2016 9:32 AM
    > To: Roberts, William C <william.c.roberts@intel.com>
    > Cc: kernel-hardening@lists.openwall.com; corbet@lwn.net; linux-
    > doc@vger.kernel.org; linux-kernel@vger.kernel.org
    > Subject: Re: [PATCH] printk: introduce kptr_restrict level 3
    >
    > On Wed, Oct 05, 2016 at 02:04:46PM -0400, william.c.roberts@intel.com wrote:
    > > From: William Roberts <william.c.roberts@intel.com>
    > >
    > > Some out-of-tree modules do not use %pK and just use %p, as it's the
    > > common C paradigm for printing pointers. Because of this,
    > > kptr_restrict has no affect on the output and thus, no way to contain
    > > the kernel address leak.
    >
    > So what? We a) don't care about out of tree modules and b) you could just triviall
    > fix them up if you care.

    Out of tree modules still affect core kernel security. I would also bet money, that somewhere
    In-tree someone has put a %p when they wanted a %pK. So this method is just quite error
    prone. We currently have a blacklist approach versus whitelist.

    >
    > No need to bloat the kernel with crap like this.

    It's unconstructive comments like this that do the whole community harm. Notice how
    responses from Kees Cook were aimed at finding a different solution to the problem and were
    very constructive. As far as "bloating" goes, it really didn't change a whole lot, most of it was moved
    lines, and adds maybe a few lines of code.

    \
     
     \ /
      Last update: 2016-10-06 15:48    [W:2.692 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site