On Thu, Apr 25, 2024 at 04:47:18PM -0700, Andrew Morton wrote: > On Thu, 25 Apr 2024 15:42:30 -0700 Kees Cook <keesc...@chromium.org> wrote: > > > > The concern about leaking image layout could be addressed by sorting the > > > output before returning to userspace. > > > > It's trivial to change permissions from the default 0400 at boot time. > > It can even have groups and ownership changed, etc. This is why we have > > per-mount-namespace /proc instances: > > > > # chgrp sysmonitor /proc/allocinfo > > # chmod 0440 /proc/allocinfo > > > > Poof, instant role-based access control. :) > > Conversely, the paranoid could set it to 0400 at boot also. > > > I'm just trying to make the _default_ safe. > > Agree with this. > > Semi-seriously, how about we set the permissions to 0000 and force > distributors/users to make a decision.
I'm ok with 0400 for now since it's consistent with slabinfo, but I'd really like to see a sysctl for debug info paranoia. We shouldn't be leaving this to the distros; we're the ones with the expertise to say what would be covered by that sysctl.
