lkml.org 
[lkml]   [2024]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] alloc_tag: Tighten file permissions on /proc/allocinfo
On Thu, Apr 25, 2024 at 2:04 PM Kent Overstreet
<kent.overstreet@linux.dev> wrote:
>
> On Thu, Apr 25, 2024 at 09:51:56PM +0100, Matthew Wilcox wrote:
> > On Thu, Apr 25, 2024 at 04:45:51PM -0400, Kent Overstreet wrote:
> > > On Thu, Apr 25, 2024 at 01:08:50PM -0700, Kees Cook wrote:
> > > > The /proc/allocinfo file exposes a tremendous about of information about
> > > > kernel build details, memory allocations (obviously), and potentially
> > > > even image layout (due to ordering). As this is intended to be consumed
> > > > by system owners (like /proc/slabinfo), use the same file permissions as
> > > > there: 0400.
> > >
> > > Err...
> > >
> > > The side effect of locking down more and more reporting interfaces is
> > > that programs that consume those interfaces now have to run as root.
> >
> > sudo cat /proc/allocinfo | analyse-that-fie
>
> Even that is still an annoyance, but I'm thinking more about a future
> daemon to collect this every n seconds - that really shouldn't need to
> be root.

Yeah, that would preclude some nice usecases. Could we maybe use
CAP_SYS_ADMIN checks instead? That way we can still use it from a
non-root process?

>
> And the "lock everything down" approach really feels like paranoia gone
> too far - what's next, /proc/cpuinfo? Do we really want to go the
> Windows approach of UAC pop ups for everything? I'd rather be going the
> opposite direction, of making it as easy as possible for users to see
> what's going on with their machine.
>
> Instead, why not a sysctl, like we already have for perf?
>
> The concern about leaking image layout could be addressed by sorting the
> output before returning to userspace.

\
 
 \ /
  Last update: 2024-05-27 18:04    [W:0.087 / U:3.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site