From: Oleg Nesterov <oleg@redhat.com>
To: Amnon Shiloh <u3557@miso.sublimeip.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>,
Pavel Emelyanov <xemul@parallels.com>,
Steven Rostedt <rostedt@goodmis.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-kernel@vger.kernel.org
Subject: Re: arch_check_bp_in_kernelspace: fix the range check
Date: Sun, 25 Nov 2012 23:55:33 +0100 [thread overview]
Message-ID: <20121125225533.GA24905@redhat.com> (raw)
In-Reply-To: <20121124134511.47C5A592076@miso.sublimeip.com>
On 11/25, Amnon Shiloh wrote:
>
> 2) I was then told (in my own words): "oh, don't worry, the vsyscall page
> has now been minimized, all it contains now is *real* system calls,
> and it always calls them".
Not sure where did you get this idea ;) From the very beginning you were
told that EMULATE mode doesn't do this.
The NATIVE mode should be fine, yes.
> 6) I just suggested an alternative: to have the whole vsyscall page
> removed on a per-process basis. I accept your reply that this is
> not possible.
Yes, this is not possible.
> 7) I suggested a third alternative: to have the vsyscall page be
> unexecutable on a per-process basis,
Like above, this is simply not possible. And at the same time the
vsyscall page is already unexecutable in EMULATE mode, but globally.
> 8) Any solution that allows a ptracer to prevent its traced process
> from entering the vsyscall page and execute there system-calls
> unchecked (thus in effect escape its jailer), would do for me.
Well. I am even more confused... probably this was already discussed
and I missed this, but.
Why do you need to _prevent_, say, sys_gettimeofday()? Why we can't
change emulate_vsyscall() to respect PTRACE_SYSCALL and report
TRAP_VSYSCALL or PTRACE_EVENT_VSYSCALL as I tried to suggest in
http://marc.info/?l=linux-kernel&m=135343635523715 ?
You previously replied that this can not work. Now that you see that
this _can_ work, could you please explain why this is not enough?
Oleg.
next prev parent reply other threads:[~2012-11-25 22:55 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-09 18:29 [PATCH] arch_check_bp_in_kernelspace: fix the range check Oleg Nesterov
2012-11-09 18:30 ` Oleg Nesterov
2012-11-19 17:47 ` Oleg Nesterov
2012-11-19 18:25 ` Steven Rostedt
2012-11-20 10:33 ` u3557
2012-11-20 15:48 ` Oleg Nesterov
2012-11-20 15:55 ` Steven Rostedt
2012-11-20 18:32 ` Oleg Nesterov
2012-11-20 23:16 ` u3557
2012-11-21 14:16 ` Oleg Nesterov
2012-11-21 17:30 ` Amnon Shiloh
2012-11-22 16:12 ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-11-22 20:57 ` Pavel Emelyanov
2012-11-23 0:20 ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range Amnon Shiloh
2012-11-23 17:45 ` Oleg Nesterov
2012-11-24 12:47 ` Amnon Shiloh
2012-11-23 17:42 ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-11-23 9:14 ` arch_check_bp_in_kernelspace: fix the range check Amnon Shiloh
2012-11-23 16:33 ` Oleg Nesterov
2012-11-23 17:05 ` Oleg Nesterov
2012-11-24 14:14 ` Amnon Shiloh
2012-11-24 13:45 ` Amnon Shiloh
2012-11-25 22:55 ` Oleg Nesterov [this message]
2012-11-25 23:48 ` Amnon Shiloh
2012-12-02 19:30 ` PTRACE_SYSCALL && vsyscall (Was: arch_check_bp_in_kernelspace: fix the range check) Oleg Nesterov
2012-12-02 23:54 ` u3557
2012-12-04 17:59 ` Oleg Nesterov
2012-12-04 22:44 ` u3557
2013-01-08 17:08 ` Pedro Alves
2013-01-09 17:52 ` Oleg Nesterov
2013-01-10 6:54 ` u3557
2013-01-12 18:12 ` Oleg Nesterov
2013-01-14 2:31 ` u3557
2013-01-14 16:01 ` Oleg Nesterov
2013-02-18 1:39 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-18 5:44 ` prctl(PR_SET_MM) Randy Dunlap
2013-02-18 15:21 ` prctl(PR_SET_MM) Steven Rostedt
2013-02-18 16:33 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-18 19:49 ` prctl(PR_SET_MM) Steven Rostedt
2013-02-19 6:25 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-20 8:39 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-20 9:38 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-20 10:51 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-20 11:16 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21 7:46 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21 8:00 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-21 8:03 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-21 8:09 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-21 22:18 ` prctl(PR_SET_MM) Andrew Morton
2013-02-21 22:42 ` prctl(PR_SET_MM) Cyrill Gorcunov
2013-02-22 1:18 ` prctl(PR_SET_MM) Amnon Shiloh
2013-02-22 14:23 ` prctl(PR_SET_MM) Denys Vlasenko
2012-12-05 9:29 ` PTRACE_SYSCALL && vsyscall (Was: arch_check_bp_in_kernelspace: fix the range check) Jan Kratochvil
2012-12-05 13:14 ` u3557
2012-11-26 9:44 ` vdso && cr " Cyrill Gorcunov
2012-11-26 12:27 ` Andrey Wagin
2012-11-26 12:55 ` Amnon Shiloh
2012-11-26 14:18 ` Cyrill Gorcunov
2012-11-26 14:26 ` vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range Amnon Shiloh
2012-11-26 14:41 ` vdso && cr Cyrill Gorcunov
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=20121125225533.GA24905@redhat.com \
--to=oleg@redhat.com \
--cc=a.p.zijlstra@chello.nl \
--cc=fweisbec@gmail.com \
--cc=gorcunov@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=rostedt@goodmis.org \
--cc=u3557@miso.sublimeip.com \
--cc=xemul@parallels.com \
/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).