[gentoo-dev] Proposed update to pax-utils.eclass

[Anthony G. Basile]

Hi everyone,

The hardened team has been working on getting PaX markings moved to 
Extended Attributes rather then putting them in a program header of the 
ELF binaries [1].  The motivation here is that this is a generally safer 
way of doing PaX markings since mangling an ELF binary can break things [2].

The last step in the process is getting an eclass on the tree which does 
both xattr as well as elf phdr based PaX markings.  We've been testing 
one for a while and we think we've clobbered all the bugs. The eclass 
deviates significantly from the one on the tree, so a I'm not sure a 
diff is the best way to present it.  The current version is on the 
hardened-dev overay [3].  It also makes use of a new utility called 
paxctl-ng which does what paxctl did but also with xattr [4].

You may want to look at some documentation too.  A updated discussion of 
PaX which includes xattr stuff is at [5].  A migration guide is at [6].

Please review.  We are in no rush to get this done, so if you find bugs 
or have concerns, add blockers to the tracker [1].


Ref.

[1] https://bugs.gentoo.org/show_bug.cgi?id=427888

[2] eg skype, https://bugs.gentoo.org/show_bug.cgi?id=461668

[3] 
http://git.overlays.gentoo.org/gitweb/?p=proj/hardened-dev.git;a=blob;f=eclass/pax-utils.eclass;h=b27d5e2f6e503cf47e9e321e441f1fe8c9c1dbd8;hb=646c49292c140491c3e1aee58a82f3c3b6a4e99f

[4] This is part of the sys-apps/elfix package.  The repo is at 
http://git.overlays.gentoo.org/gitweb/?p=proj/elfix.git;a=summary

[5] http://www.gentoo.org/proj/en/hardened/pax-quickstart.xml

[6] http://www.gentoo.org/proj/en/hardened/pax-migrate-xattr.xml


-- 
Anthony G. Basile, Ph.D.
Gentoo Linux Developer [Hardened]
E-Mail    : blueness@g.o
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