Re: 2.6.25 Kernel - Problems with capabilities

From: serge
Date: Sun Apr 20 2008 - 20:05:01 EST


Quoting David (david@xxxxxxxxxxxxxxx):
> Casey Schaufler wrote:
>> Do you have a libcap that reflects the change from 32 capabilities
>> to 64? You'll be looking for libcap.so.2.06 or thereabouts.
>>
> Adding libcap-2.08 and recompiling ntpd has fixed the issue, and I'm now
> running normally, thanks!

I don't understand why, though. Looking at the ntpd code (ntp-4.2.4p4)
it just does a cap_set_proc(cap_from_text("X=epi")); It should simply
be sending in the _LINUX_CAPABILITY_VERSION which shipped with libcap,
which should have been _V1, and the kernel should honor that so long as
you didn't try to send in caps > 31, which ntpd wasn't.

> Was this userspace visible change planned in advance for 2.6.25 ? ... as I
> guess a few other people with venerable old userspace components may come
> across this issue.
>
> Cheers
> David

It's been in the works a long time and we thought we'd done pretty
well with backward compatibility. I really don't see why you had
that failure!

Do you know which version of libcap you had before?

thanks,
-serge
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/