Re: [RFC] [PATCH -mm] oom_kill: remove uid==0 checks

From: Andrew Morton
Date: Thu Dec 20 2007 - 19:41:09 EST


On Wed, 12 Dec 2007 15:06:17 -0800
Andrew Morgan <morgan@xxxxxxxxxx> wrote:

> Serge E. Hallyn wrote:
> > Andrew, I've cc:d you here bc in doing this patch I noticed that your
> > 64-bit capabilities patch switched this code from an explicit check
> > of cap_t(p->cap_effective) to using __capable(). That means that
> > now being glossed over by the oom killer means PF_SUPERPRIV will
> > be set. Is that intentional?
>
> Yes, I switched the check because the old one didn't work with the new
> capability representation.
>
> However, I had not thought this aspect of this replacement through. At
> the time, it seemed obvious but in this case it actually depends on
> whether you think using privilege (PF_SUPERPRIV) means "benefited from
> privilege", or "successfully completed a privileged operation".
>
> I suspect, in this case, the correct thing to do is add the equivalent of:
>
> #define CAPABLE_PROBE_ONLY(a,b) (!security_capable(a,b))
>
> and use that in the code in question. That is, return to the old
> behavior in a way that will not break if we ever need to add more bits.

I'm struggling to understand whether the above was an ack, a nack or a
quack.

> Thanks for finding this.

>From that I'll assume ack ;)
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