kernel-hardening.lists.openwall.com archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: "Reshetova, Elena" <elena.reshetova@intel.com>
Cc: "kernel-hardening@lists.openwall.com"
	<kernel-hardening@lists.openwall.com>,
	"luto@kernel.org" <luto@kernel.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"bp@alien8.de" <bp@alien8.de>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"tytso@mit.edu" <tytso@mit.edu>
Subject: Re: [RFC PATCH] x86/entry/64: randomize kernel stack offset upon system call
Date: Fri, 8 Feb 2019 15:26:43 +0100	[thread overview]
Message-ID: <20190208142642.GJ32511@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <2236FBA76BA1254E88B949DDB74E612BA4BB7580@IRSMSX102.ger.corp.intel.com>

On Fri, Feb 08, 2019 at 01:20:09PM +0000, Reshetova, Elena wrote:
> > On Fri, Feb 08, 2019 at 02:15:49PM +0200, Elena Reshetova wrote:

> > 
> > Why can't we change the stack offset periodically from an interrupt or
> > so, and then have every later entry use that.
> 
> Hm... This sounds more complex conceptually - we cannot touch
> stack when it is in use, so we have to periodically probe for a 
> good time (when process is in userspace I guess) to change it from an interrupt?
> IMO trampoline stack provides such a good clean place for doing it and we
> have stackleak there doing stack cleanup, so would make sense to keep
> these features operating together.

The idea was to just change a per-cpu (possible per-task if you ctxsw
it) offset that is used on entry to offset the stack.

So only entries after the change will have the updated offset, any
in-progress syscalls will continue with their current offset and will be
unaffected.

  reply	other threads:[~2019-02-08 14:26 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-08 12:15 [RFC PATCH] Early version of thread stack randomization Elena Reshetova
2019-02-08 12:15 ` [RFC PATCH] x86/entry/64: randomize kernel stack offset upon system call Elena Reshetova
2019-02-08 13:05   ` Peter Zijlstra
2019-02-08 13:20     ` Reshetova, Elena
2019-02-08 14:26       ` Peter Zijlstra [this message]
2019-02-09 11:13         ` Reshetova, Elena
2019-02-09 18:25           ` Andy Lutomirski
2019-02-11  6:39             ` Reshetova, Elena
2019-02-11 15:54               ` Andy Lutomirski
2019-02-12 10:16                 ` Perla, Enrico
2019-02-14  7:52                   ` Reshetova, Elena
2019-02-19 14:47                     ` Jann Horn
2019-02-20 22:20                     ` Kees Cook
2019-02-21  6:37                       ` Andy Lutomirski
2019-02-21 13:20                         ` Jann Horn
2019-02-21 15:49                           ` Andy Lutomirski
2019-02-20 22:15                   ` Kees Cook
2019-02-20 22:53                     ` Kees Cook
2019-02-21 23:29                       ` Kees Cook
2019-02-27 11:03                         ` Reshetova, Elena
2019-02-21  9:35                     ` Perla, Enrico
2019-02-21 17:23                       ` Kees Cook
2019-02-21 17:48                         ` Perla, Enrico
2019-02-21 19:18                           ` Kees Cook
2019-02-20 21:51         ` Kees Cook
2019-02-08 15:15       ` Peter Zijlstra
2019-02-09 11:38         ` Reshetova, Elena
2019-02-09 12:09           ` Greg KH
2019-02-11  6:05             ` Reshetova, Elena
2019-02-08 16:34   ` Andy Lutomirski
2019-02-20 22:03     ` Kees Cook
2019-02-08 21:28   ` Kees Cook
2019-02-11 12:47     ` Reshetova, Elena
2019-02-20 22:04   ` Kees Cook

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=20190208142642.GJ32511@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=bp@alien8.de \
    --cc=elena.reshetova@intel.com \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=tytso@mit.edu \
    /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).