Re: Possible problem in linux file posix capabilities

From: Serge E. Hallyn
Date: Mon Feb 18 2008 - 08:45:05 EST


Quoting Casey Schaufler (casey@xxxxxxxxxxxxxxxx):
>
> --- "Serge E. Hallyn" <serue@xxxxxxxxxx> wrote:
>
> > ....
> >
> > Two quick fixes for you right now (apart from the one you've already
> > got :) would be
> >
> > 1. give wireshark cap_kill, by doing something like
> >
> > capset cap_kill=ep /bin/wireshark
> >
> > 2. compile a kernel with SECURITY_FILE_CAPABILITIES=n
> >
> > Andrew, this pretty much was bound to happen... we need to figure out
> > what our approach here should be. My preference is still to allow
> > signals when p->uid==current->uid so long as !SECURE_NOROOT. Then as
> > people start using secure_noroot process trees they at least must know
> > what they're asking for.
> >
> > An alternative stance is to accept these things as they come up and try
> > to quickly work with the authors of such programs to work around it. I
> > suppose in a security sense that's the superior way :) But it also
> > seems likely to lead to most people choosing option 2 above and not
> > bothering to fix the problem.
>
> I probably just missed it when it went by, but do you have some
> test cases for file capabilities lying about that I might use?

Yup, please download the latest ltp cvs tree (I don't think it's in any
release yet, though I may be wrong) and look under
testcaes/kernel/security/filecaps. Or just do

cd ltp
make && make install && ./runltp -s filecap

-serge
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