Notify special task kill using wait* functions

[John Wood]

Hi,

On Fri, Apr 09, 2021 at 07:28:20PM -0400, Valdis Klētnieks wrote:
> On Fri, 09 Apr 2021 08:06:21 -0700, Andi Kleen said:
>
> > Thinking more about it what I wrote above wasn't quite right. The cache
> > would only need to be as big as the number of attackable services/suid
> > binaries. Presumably on many production systems that's rather small,
> > so a cache (which wouldn't actually be a cache, but a complete database)
> > might actually work.
>
> You also need to consider non-suid things called by suid things that don't
> sanitize input sufficiently before invocation...
>
> Thinking about at - is it really a good thing to try to do this in kernelspace?
> Or is 'echo 1 > /proc/sys/kernel/print-fatal-signals' and a program to watch
> the dmesg and take action more appropriate?  A userspace monitor would
> have more options (though a slightly higher risk of race conditions).
>

Thanks for the ideas. I need some time to send a formal proposal that
works properly. I would like to get feedback at that moment. I think it
would be better to discuss about the real patch.

Again, thanks.
John Wood