linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>, Jiri Olsa <jolsa@redhat.com>,
	Andi Kleen <andi@firstfloor.org>, Jiri Olsa <jolsa@kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [PATCH] fs/proc/kcore.c: Omit kernel text area for hardened usercopy feature
Date: Tue, 6 Sep 2016 12:41:14 -0700	[thread overview]
Message-ID: <20160906194114.GP5871@two.firstfloor.org> (raw)
In-Reply-To: <CA+55aFzx1Z6aN9XN4SnFJtMjXvfk5ex9L7QWR=k39G0k9r0Jwg@mail.gmail.com>

On Tue, Sep 06, 2016 at 11:34:28AM -0700, Linus Torvalds wrote:
> On Tue, Sep 6, 2016 at 10:56 AM, Kees Cook <keescook@chromium.org> wrote:
> >
> > In the meantime, how about continuing to use a bounce buffer like
> > already done in the vmalloc_or_module_addr() case immediately above?
> 
> Yes please. Let's not make up even more of the user access functions
> with magical properties, for some special-case code in /proc/kcore.

I suspect it's more than just /proc/kcore, there could be also 
legitimate cases to read kernel text from /dev/mem or /dev/kmem

I suppose could add bounce buffers everywhere.

-Andi

  reply	other threads:[~2016-09-06 19:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-02 12:25 [PATCH] fs/proc/kcore.c: Omit kernel text area for hardened usercopy feature Jiri Olsa
2016-09-02 15:17 ` Andi Kleen
2016-09-02 16:15   ` Jiri Olsa
2016-09-05  8:47   ` Jiri Olsa
2016-09-05 16:27     ` Andi Kleen
2016-09-06 17:56     ` Kees Cook
2016-09-06 18:34       ` Linus Torvalds
2016-09-06 19:41         ` Andi Kleen [this message]
2016-09-06 19:48           ` Linus Torvalds
2016-09-07 17:17             ` Kees Cook
2016-09-07 17:24               ` Linus Torvalds
2016-09-07  7:32       ` Jiri Olsa
2016-09-07 16:38         ` Andi Kleen
2016-09-07 16:58           ` Linus Torvalds
2016-09-07 19:25             ` Jiri Olsa
2016-09-07 21:24               ` Jiri Olsa
2016-09-07 22:52                 ` Linus Torvalds

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160906194114.GP5871@two.firstfloor.org \
    --to=andi@firstfloor.org \
    --cc=adrian.hunter@intel.com \
    --cc=jolsa@kernel.org \
    --cc=jolsa@redhat.com \
    --cc=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).