Re: [PATCH v3 2/3] Documentation: security-bugs: explain what is and is not a security bug

Willy Tarreau <[email protected]>
Newsgroups org.kernel.vger.workflows,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Wed, May 13, 2026 at 06:52:00AM -0600, Jonathan Corbet wrote:
> Willy Tarreau <[email protected]> writes:
> 
> > On Wed, May 13, 2026 at 12:29:34PM +0200, Greg KH wrote:
> >> On Tue, May 12, 2026 at 11:20:51AM -0600, Jonathan Corbet wrote:
> >> > Willy Tarreau <[email protected]> writes:
> 
> >> > > +* **Capability-based protection**:
> >> > > +
> >> > > +  * users not having the ``CAP_SYS_ADMIN`` capability may not alter the
> >> > > +    kernel's configuration, memory nor state, change other users' view of the
> >> > > +    file system layout, grant any user capabilities they do not have, nor
> >> > > +    affect the system's availability (shutdown, reboot, panic, hang, or making
> >> > > +    the system unresponsive via unbounded resource exhaustion).
> >> > 
> >> > That is pretty demonstrably not true, and will likely elicit challenges
> >> > at some point.  There are a lot of "make me root" capabilities that
> >> > enable users to do all of those things; consider CAP_DAC_OVERRIDE as an
> >> > obvious example.  I think that just about all of the capabilities will
> >> > enable at least one of those things - that's why the capabilities exist
> >> > in the first place.  So I think this needs to be written far more
> >> > generally.
> >> 
> >> You are right, there are more capabilities, but we get bug reports all
> >> the time that basically come down to "a user with CAP_SYS_ADMIN can go
> >> and do..." which are pointless for us to be handling.  Just got one a
> >> few minutes ago, so LLMs are churning this crap out quite frequently.
> >> 
> >> So any rewording of this to prevent us from getting these pointless
> >> reports would be great.
> >
> > Honestly we're seeing this through the angle of a patch that lists a
> > single paragraph but the doc is already becoming quite long. I'm a bit
> > afraid of adding long enumerations, or sentences which do not immediately
> > translate to something recognizable by reporters. Not that it cannot be
> > done, but I think the current situation warrants incremental improvements
> > by fixing what doesn't work well. And indeed most of the capabilities
> > based reports currently revolve around "I already have CAP_{SYS,NET}_ADMIN
> > and ...". That might remain a good start for now.
> 
> I definitely wouldn't argue for making it longer, and enumerating all of
> the make-me-root capabilities would be silly.  I would consider just
> replacing CAP_SYS_ADMIN with "elevated capabilities" or some such.  That
> might rule out legitimate reports where some capability provides an
> access it shouldn't, but I suspect you could live with that :)

I think it could indeed work like this, without denaturating the rest
of the paragraph and having broader coverage. Do you think you could
amend/update it ? I'm not trying to add you any burden, it's just that
it will take me more time before I provide an update :-/

Thanks,
Willy
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.