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authorAnthony G. Basile <blueness@gentoo.org>2012-11-11 00:18:35 (GMT)
committerAnthony G. Basile <blueness@gentoo.org>2012-11-11 00:18:35 (GMT)
commiteb3a2e198c926aca7063aa036793bb94bfbec1ef (patch)
treec08bdf210b4913d238928068e1b1256cd18447bd
parentClear out the branch in case it causes problems (diff)
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pax-utils.eclass: updated eclass to handle PT_PAX and XT_PAXXT_PAX
-rw-r--r--profiles/eclass/pax-utils.eclass198
1 files changed, 198 insertions, 0 deletions
diff --git a/profiles/eclass/pax-utils.eclass b/profiles/eclass/pax-utils.eclass
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+# Copyright 1999-2011 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: /var/cvsroot/gentoo-x86/eclass/pax-utils.eclass,v 1.18 2012/04/06 18:03:54 blueness Exp $
+
+# @ECLASS: pax-utils.eclass
+# @MAINTAINER:
+# The Gentoo Linux Hardened Team <hardened@gentoo.org>
+# @AUTHOR:
+# Original Author: Kevin F. Quinn <kevquinn@gentoo.org>
+# Modifications for bug #365825, @ ECLASS markup: Anthony G. Basile <blueness@gentoo.org>
+# Modifications for bug #431092: Anthony G. Basile <blueness@gentoo.org>
+# @BLURB: functions to provide pax markings
+# @DESCRIPTION:
+# This eclass provides support for manipulating PaX markings on ELF binaries,
+# wrapping the use of the paxctl and scanelf utilities. It decides which to
+# use depending on what is installed on the build host, preferring paxctl to
+# scanelf. If paxctl is not installed, we fall back to scanelf since it is
+# always present. However, currently scanelf doesn't do all that paxctl can.
+#
+# To control what markings are made, set PAX_MARKINGS in /etc/portage/make.conf
+# to contain either "PT", "XT" or "none". If PAX_MARKINGS contains "PT", and
+# the necessary utility is installed, then PT_PAX_FLAGS markings will be made.
+# Similarly, if PAX_MARKINGS contains "XT", then xattr markings will be made.
+# If PAX_MARKINGS is set to "none", no markings will be made.
+
+if [[ ${___ECLASS_ONCE_PAX_UTILS} != "recur -_+^+_- spank" ]] ; then
+___ECLASS_ONCE_PAX_UTILS="recur -_+^+_- spank"
+
+# Default to PT markings.
+PAX_MARKINGS=${PAX_MARKINGS:="PT XT"}
+
+# @FUNCTION: pax-mark
+# @USAGE: <flags> {<ELF files>}
+# @RETURN: Shell true if we succeed, shell false otherwise
+# @DESCRIPTION:
+# Marks <ELF files> with provided PaX <flags>
+#
+# Flags are passed directly to the utilities unchanged. Possible flags at the
+# time of writing, taken from /sbin/paxctl, are:
+#
+# p: disable PAGEEXEC P: enable PAGEEXEC
+# e: disable EMUTRMAP E: enable EMUTRMAP
+# m: disable MPROTECT M: enable MPROTECT
+# r: disable RANDMMAP R: enable RANDMMAP
+# s: disable SEGMEXEC S: enable SEGMEXEC
+#
+# Default flags are 'PeMRS', which are the most restrictive settings. Refer
+# to http://pax.grsecurity.net/ for details on what these flags are all about.
+# Do not use the obsolete flag 'x'/'X' which has been deprecated.
+#
+# Please confirm any relaxation of restrictions with the Gentoo Hardened team.
+# Either ask on the gentoo-hardened mailing list, or CC/assign hardened@g.o on
+# the bug report.
+
+pax-mark() {
+
+ local f # loop over paxables
+ local flags # pax flags
+ local pt_fail=0 pt_failures="" # record PT_PAX failures
+ local xt_fail=0 xt_failures="" # record xattr PAX marking failures
+ local ret=0 # overal return code of this function
+
+ # You can call pax-mark with/out leading '-' on flags
+ flags=${1//-}
+ shift
+
+ if has PT ${PAX_MARKINGS}; then
+
+ #First try paxctl-ng
+ if type -p paxctl-ng > /dev/null; then
+ einfo "PT PaX marking -${flags}"
+ _pax_list_files einfo "$@"
+ for f in "$@"; do
+ paxctl-ng -L -${flags} "${f}" && continue
+ pt_fail=1
+ pt_failures="${pt_failures} ${f}"
+ done
+
+ #Next try paxctl
+ elif type -p paxctl > /dev/null; then
+ einfo "PT PaX marking -${flags}"
+ _pax_list_files einfo "$@"
+ for f in "$@"; do
+ # First, try modifying the existing PAX_FLAGS header
+ paxctl -q${flags} "${f}" && continue
+ # Second, try stealing the (unused under PaX) PT_GNU_STACK header
+ paxctl -qc${flags} "${f}" && continue
+ # Third, creating a PT_PAX header (works on ET_EXEC)
+ paxctl -qC${flags} "${f}" && continue
+ pt_fail=1
+ pt_failures="${pt_failures} ${f}"
+ done
+
+ #Finally fall back on scanelf
+ elif type -p scanelf > /dev/null && [[ ${PAX_MARKINGS} != "none" ]]; then
+ einfo "Fallback PaX marking -${flags}"
+ _pax_list_files einfo "$@"
+ scanelf -Xxz ${flags} "$@"
+
+ #We failed to set PT_PAX flags
+ elif [[ ${PAX_MARKINGS} != "none" ]]; then
+ pt_failures="$*"
+ pt_fail=1
+ fi
+
+ if [[ ${pt_fail} == 1 ]]; then
+ ewarn "Failed to set XT_PAX markings -${flags} for:"
+ _pax_list_files ewarn ${pt_failures}
+ ret=1
+ fi
+ fi
+
+ if has XT ${PAX_MARKINGS}; then
+
+ #First try paxctl-ng
+ if type -p paxctl-ng > /dev/null; then
+ einfo "XT PaX marking -${flags}"
+ _pax_list_files einfo "$@"
+ for f in "$@"; do
+ paxctl-ng -l -${flags} "${f}" && continue
+ xt_fail=1
+ xt_failures="${tx_failures} ${f}"
+ done
+
+ #Next try set/get
+ elif type -p setfattr > /dev/null; then
+ einfo "XT PaX marking -${flags}"
+ _pax_list_files einfo "$@"
+ for f in "$@"; do
+ setfattr -n "user.pax.flags" -v "${flags}" "${f}" && continue
+ xt_fail=1
+ xt_failures="${tx_failures} ${f}"
+ done
+
+ #We failed to set PT_PAX flags
+ elif [[ ${PAX_MARKINGS} != "none" ]]; then
+ pt_failures="$*"
+ pt_fail=1
+ fi
+
+ if [[ ${xt_fail} == 1 ]]; then
+ ewarn "Failed to set XT_PAX markings -${flags} for:"
+ _pax_list_files ewarn ${xt_failures}
+ ret=1
+ fi
+ fi
+
+ [[ ${ret} == 1 ]] && ewarn "Executables may be killed by PaX kernels."
+
+ return ${ret}
+}
+
+# @FUNCTION: list-paxables
+# @USAGE: {<files>}
+# @RETURN: Subset of {<files>} which are ELF executables or shared objects
+# @DESCRIPTION:
+# Print to stdout all of the <files> that are suitable to have PaX flag
+# markings, i.e., filter out the ELF executables or shared objects from a list
+# of files. This is useful for passing wild-card lists to pax-mark, although
+# in general it is preferable for ebuilds to list precisely which ELFS are to
+# be marked. Often not all the ELF installed by a package need remarking.
+# @EXAMPLE:
+# pax-mark -m $(list-paxables ${S}/{,usr/}bin/*)
+list-paxables() {
+ file "$@" 2> /dev/null | grep -E 'ELF.*(executable|shared object)' | sed -e 's/: .*$//'
+}
+
+# @FUNCTION: host-is-pax
+# @RETURN: Shell true if the build process is PaX enabled, shell false otherwise
+# @DESCRIPTION:
+# This is intended for use where the build process must be modified conditionally
+# depending on whether the host is PaX enabled or not. It is not intedened to
+# determine whether the final binaries need PaX markings. Note: if procfs is
+# not mounted on /proc, this returns shell false (e.g. Gentoo/FBSD).
+host-is-pax() {
+ grep -qs ^PaX: /proc/self/status
+}
+
+
+# INTERNAL FUNCTIONS
+# ------------------
+#
+# These functions are for use internally by the eclass - do not use
+# them elsewhere as they are not supported (i.e. they may be removed
+# or their function may change arbitratily).
+
+# Display a list of things, one per line, indented a bit, using the
+# display command in $1.
+_pax_list_files() {
+ local f cmd
+ cmd=$1
+ shift
+ for f in "$@"; do
+ ${cmd} " ${f}"
+ done
+}
+
+fi