Re: RT linker, rpath and security

[tlaronde%polynum.com@localhost]

Le Thu, May 11, 2023 at 09:45:07AM -0400, Greg Troxel a écrit :
>[...] 
>   - Examine what pkgsrc is doing already.  I would not be surprised to
>     find that if a binary gets built with an RPATH outside of pkgsrc
>     (and not base X and base base) that this is an error, but maybe only
>     in developer mode.  This might also surface some interesting data.

FWIW (I have started to work on a utility to check), here is an example
of something that could perhaps be an incentive to look at the problem
more closely:

$ readelf -d /usr/pkg/sbin/visudo | egrep "NEEDED|RPATH"

 0x0000000000000001 (NEEDED)             Shared library: [libc.so.12]
 0x000000000000000f (RPATH)              Library rpath: [/usr/pkg/lib]

visudo depends only on the system libc (I'm on NetBSD 9.3) and 
loads the dynshared /usr/pkg/libexec/sudo_noexec.so (the full path is
given) but still there is a rpath registered pointing to /usr/pkg/lib.

If a package would be installing a libc.so.12 under /usr/pkg/lib, this
one will be used instead of the system one.

This is the kind of "devil in the details" that could be worth looking
at.
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
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