Re: [PATCH 2/2] docs: admin-guide: Not every security bug should be kept hidden

From: Krzysztof Kozlowski
Date: Thu Aug 27 2020 - 10:55:33 EST


On Thu, Aug 27, 2020 at 02:11:23PM +0200, Greg Kroah-Hartman wrote:
> On Thu, Aug 27, 2020 at 12:53:19PM +0200, Krzysztof Kozlowski wrote:
> > Document describes the process of handling security bugs but does not
> > mention any criteria what is a "security bug". Unlike
> > submitting-patches.rst which explicitly says - publicly exploitable bug.
> >
> > Many NULL pointer exceptions, off-by-one errors or overflows tend
> > to look like security bug, so there might be a temptation to discuss
> > them behind security list which is not an open list.
> >
> > Such discussion limits the amount of testing and independent reviewing.
> > Sacrificing open discussion is understandable in the case of real
> > security issues but not for regular bugs. These should be discussed
> > publicly.
> >
> > At the end, "security problems are just bugs".
> >
> > Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> >
> > ---
> >
> > Follow up to:
> > https://lore.kernel.org/linux-usb/1425ab4f-ef7e-97d9-238f-0328ab51eb35@xxxxxxxxxxx/
> > ---
> > Documentation/admin-guide/security-bugs.rst | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/admin-guide/security-bugs.rst b/Documentation/admin-guide/security-bugs.rst
> > index c32eb786201c..7ebddbd4bbcd 100644
> > --- a/Documentation/admin-guide/security-bugs.rst
> > +++ b/Documentation/admin-guide/security-bugs.rst
> > @@ -78,6 +78,12 @@ include linux-distros from the start. In this case, remember to prefix
> > the email Subject line with "[vs]" as described in the linux-distros wiki:
> > <http://oss-security.openwall.org/wiki/mailing-lists/distros#how-to-use-the-lists>
> >
> > +Fixes for non-exploitable bugs which do not pose a real security risk, should
> > +be disclosed in a regular way of submitting patches to Linux kernel (see
> > +:ref:`Documentation/process/submitting-patches.rst <submitting-patches>`).
> > +Just because patch fixes some off-by-one or NULL pointer exception, does not
> > +classify it as a security bug which should be discussed in closed channels.
>
> I said this on another thread, but almost always, when we get reports
> like this on security@k.o, we do push them back to public lists.

Then let's hope that next time someone will read this documentation
before submitting such report to @security.

>
> For the most part, this paragraph is not going to help much (mostly for
> the reason that no one seems to read it, but that's a different
> topic...)

All of our documentation is our wish that someone will read it and
follow it. Just because people might not follow it, is not necessarily a
reason to skip documentation.

> We get crazy reports all the time, and that's fine, because
> sometimes, there is a real issue in some of them. And for that, we do
> want to be careful. We also have many docuemented "off-by-one" bugs
> that were real security issues (there's a blog post somewhere about how
> a developer turned such a bug into a root hole, can't find it right
> now...)

I understand. That's why I also mentioned the criteria of exploitable
and posing a security risk. First case (even stricter - publicly
exploitable) is already mentioned in submitting-patches so I am not
changing the current status.

I merely want to document it based on recent discussion.

> So while I understand the temptation here, based on the current
> security@k.o traffic, I doubt this will really change much :(
>
> Also, you should have cc:ed that group when you are changing things that
> will affect them.

Indeed, I will update the maintainers as well.

Best regards,
Krzysztof