From: Nick Desaulniers <ndesaulniers@google.com>
To: rostedt@goodmis.org
Cc: salyzyn@android.com, LKML <linux-kernel@vger.kernel.org>,
mingo@redhat.com, kernel-team@android.com,
stable@vger.kernel.org
Subject: Re: [PATCH] tracing: do not leak kernel addresses
Date: Thu, 26 Jul 2018 09:32:07 -0700 [thread overview]
Message-ID: <CAKwvOdknFPpyQx17EbixnydJukuX4kH8=xVTS_9qnsERKCoPkQ@mail.gmail.com> (raw)
In-Reply-To: <20180726112245.3c1bf91d@gandalf.local.home>
On Thu, Jul 26, 2018 at 8:22 AM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Thu, 26 Jul 2018 08:14:08 -0700
> Mark Salyzyn <salyzyn@android.com> wrote:
>
> > Thank you Steve, much appreciated feedback, I have asked the security
> > developers to keep this in mind and come up with a correct fix.
> >
> > The correct fix that meets your guidelines would _not_ be suitable for
> > stable due to the invasiveness it sounds, only for the latest will such
> > a rework make sense. As such, the fix proposed in this patch is the only
> > one that meets the bar for stable patch simplicity, and merely(!) needs
> > to state that if the fix is taken, perf and trace are broken.
> >
> > Posting this patch publicly on the lists, that may never be applied, may
> > be the limit of our responsibility for a fix to stable kernel releases,
> > to be optionally applied by vendors concerned with this CVE criteria?
> >
>
> The patch breaks the code it touches. It makes it useless.
Doesn't that depend on kptr_restrict, or would it be broken if
kptr_restrict was set to 0?
> If you want
> something for stable, add a command line parameter that just disables
> the creation of that file. Otherwise you will break usespace and that
> will be a definitely NAK from Linus, and for stable itself. This is a
> very minor security issue, and does not justify breaking userspace
> applications. I would be very upset if a new stable release broke both
> perf and trace-cmd's ability to read certain trace events.
I don't disagree.
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2018-07-26 16:32 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-25 20:22 [PATCH] tracing: do not leak kernel addresses Mark Salyzyn
2018-07-25 21:14 ` Nick Desaulniers
2018-07-26 1:07 ` Steven Rostedt
2018-07-26 15:14 ` Mark Salyzyn
2018-07-26 15:22 ` Steven Rostedt
2018-07-26 16:32 ` Nick Desaulniers [this message]
2018-07-26 16:37 ` Steven Rostedt
2018-07-26 16:59 ` Nick Desaulniers
2018-07-26 21:56 ` Nick Desaulniers
2018-07-26 15:31 ` Greg KH
2018-07-26 16:52 ` Nick Desaulniers
2018-07-26 22:15 ` Steven Rostedt
2018-07-27 12:07 ` Jordan Glover
2018-07-27 13:40 ` Jann Horn
2018-07-27 13:47 ` Steven Rostedt
2018-07-27 18:13 ` Nick Desaulniers
2018-07-27 18:31 ` Steven Rostedt
[not found] ` <CAMx4XWv3OazvURuN1XU2+5C5tNDzPuTniMn_T=XTA4P8_uwS_A@mail.gmail.com>
2018-07-27 18:47 ` Jann Horn
2018-07-27 18:58 ` Jann Horn
2018-07-27 19:54 ` Theodore Y. Ts'o
2018-07-27 20:11 ` Steven Rostedt
2018-07-27 20:21 ` Theodore Y. Ts'o
2018-07-27 20:53 ` Steven Rostedt
2018-07-27 22:05 ` Sandeep Patil
2018-07-28 0:04 ` Theodore Y. Ts'o
2018-07-30 14:35 ` Sandeep Patil
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