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.
next prev parent 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
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