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# Copyright 1999-2011 Gentoo Foundation |
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# Copyright 1999-2012 Gentoo Foundation |
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# Distributed under the terms of the GNU General Public License v2 |
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# Distributed under the terms of the GNU General Public License v2 |
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# $Header: /var/cvsroot/gentoo-x86/eclass/pax-utils.eclass,v 1.18 2012/04/06 18:03:54 blueness Exp $ |
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# $Header: /var/cvsroot/gentoo-x86/eclass/pax-utils.eclass,v 1.18 2012/04/06 18:03:54 blueness Exp $ |
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# @AUTHOR: |
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# @AUTHOR: |
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# Original Author: Kevin F. Quinn <kevquinn@gentoo.org> |
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# Original Author: Kevin F. Quinn <kevquinn@gentoo.org> |
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# Modifications for bug #365825, @ ECLASS markup: Anthony G. Basile <blueness@gentoo.org> |
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# Modifications for bug #365825, @ ECLASS markup: Anthony G. Basile <blueness@gentoo.org> |
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# Modifications for bug #431092: Anthony G. Basile <blueness@gentoo.org> |
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# @BLURB: functions to provide pax markings |
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# @BLURB: functions to provide pax markings |
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# @DESCRIPTION: |
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# @DESCRIPTION: |
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# |
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# This eclass provides support for manipulating PaX markings on ELF binaries, |
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# This eclass provides support for manipulating PaX markings on ELF binaries, |
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# wrapping the use of the paxctl and scanelf utilities. It decides which to |
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# whether the system is using legacy PT_PAX markings or the newer XATTR_PAX. |
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# use depending on what is installed on the build host, preferring paxctl to |
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# The eclass wraps the use of paxctl-ng, paxctl, set/getattr and scanelf utilities, |
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# scanelf. If paxctl is not installed, we fall back to scanelf since it is |
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# deciding which to use depending on what's installed on the build host, and |
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# always present. However, currently scanelf doesn't do all that paxctl can. |
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# whether we're working with PT_PAX, XATTR_PAX or both. |
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# |
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# |
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# To control what markings are made, set PAX_MARKINGS in /etc/make.conf to |
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# To control what markings are made, set PAX_MARKINGS in /etc/portage/make.conf |
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# contain either "PT" or "none". If PAX_MARKINGS is set to "PT", and the |
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# to contain either "PT", "XT" or "none". The default is to attempt both |
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# necessary utility is installed, the PT_PAX_FLAGS markings will be made. If |
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# PT_PAX and XATTR_PAX. |
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# PAX_MARKINGS is set to "none", no markings will be made. |
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if [[ ${___ECLASS_ONCE_PAX_UTILS} != "recur -_+^+_- spank" ]] ; then |
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if [[ ${___ECLASS_ONCE_PAX_UTILS} != "recur -_+^+_- spank" ]] ; then |
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___ECLASS_ONCE_PAX_UTILS="recur -_+^+_- spank" |
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___ECLASS_ONCE_PAX_UTILS="recur -_+^+_- spank" |
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# Default to PT markings. |
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# Default to PT markings. |
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PAX_MARKINGS=${PAX_MARKINGS:="PT"} |
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PAX_MARKINGS=${PAX_MARKINGS:="PT XT"} |
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# @FUNCTION: pax-mark |
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# @FUNCTION: pax-mark |
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# @USAGE: <flags> {<ELF files>} |
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# @USAGE: <flags> {<ELF files>} |
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# @DESCRIPTION: |
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# @DESCRIPTION: |
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# Marks <ELF files> with provided PaX <flags> |
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# Marks <ELF files> with provided PaX <flags> |
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# |
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# |
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# Flags are passed directly to the utilities unchanged. Possible flags at the |
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# Flags are passed directly to the utilities unchanged |
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# time of writing, taken from /sbin/paxctl, are: |
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# |
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# |
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# p: disable PAGEEXEC P: enable PAGEEXEC |
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# p: disable PAGEEXEC P: enable PAGEEXEC |
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# e: disable EMUTRMAP E: enable EMUTRMAP |
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# e: disable EMUTRMAP E: enable EMUTRMAP |
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# |
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# Default flags are 'PeMRS', which are the most restrictive settings. Refer |
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# Default flags are 'PeMRS', which are the most restrictive settings. Refer |
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# to http://pax.grsecurity.net/ for details on what these flags are all about. |
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# to http://pax.grsecurity.net/ for details on what these flags are all about. |
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# Do not use the obsolete flag 'x'/'X' which has been deprecated. |
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# |
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# |
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# Please confirm any relaxation of restrictions with the Gentoo Hardened team. |
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# Please confirm any relaxation of restrictions with the Gentoo Hardened team. |
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# Either ask on the gentoo-hardened mailing list, or CC/assign hardened@g.o on |
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# Either ask on the gentoo-hardened mailing list, or CC/assign hardened@g.o on |
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# the bug report. |
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# the bug report. |
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pax-mark() { |
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pax-mark() { |
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local f flags fail=0 failures="" zero_load_alignment |
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# Ignore '-' characters - in particular so that it doesn't matter if |
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local f # loop over paxables |
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# the caller prefixes with - |
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local flags # pax flags |
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flags=${1//-} |
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local pt_fail=0 pt_failures="" # record PT_PAX failures |
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local xt_fail=0 xt_failures="" # record xattr PAX marking failures |
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local ret=0 # overal return code of this function |
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# Only the actual PaX flags and z are accepted |
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# 1. The leading '-' is optional |
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# 2. -C -c only make sense for paxctl, but are unnecessary |
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# because we progressively do -q -qc -qC |
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# 3. z is allowed for the default |
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flags="${1//[!zPpEeMmRrSs]}" |
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[ "${flags}" ] || return 0 |
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shift |
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shift |
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# Try paxctl, then scanelf. paxctl is preferred. |
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if type -p paxctl > /dev/null && has PT ${PAX_MARKINGS}; then |
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# z = default. For XATTR_PAX, the default is no xattr field at all |
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# Try paxctl, the upstream supported tool. |
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local dodefault="" |
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einfo "PT PaX marking -${flags}" |
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[ "${flags//[!z]}" ] && dodefault="yes" |
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_pax_list_files einfo "$@" |
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for f in "$@"; do |
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if has PT ${PAX_MARKINGS}; then |
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# First, try modifying the existing PAX_FLAGS header |
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paxctl -q${flags} "${f}" && continue |
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#First try paxctl -> this might try to create/convert program headers |
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# Second, try stealing the (unused under PaX) PT_GNU_STACK header |
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if type -p paxctl > /dev/null; then |
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paxctl -qc${flags} "${f}" && continue |
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einfo "PT PaX marking -${flags} with paxctl" |
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# Third, try pulling the base down a page, to create space and |
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_pax_list_files einfo "$@" |
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# insert a PT_GNU_STACK header (works on ET_EXEC) |
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for f in "$@"; do |
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paxctl -qC${flags} "${f}" && continue |
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# First, try modifying the existing PAX_FLAGS header |
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# |
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paxctl -q${flags} "${f}" && continue |
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# prelink is masked on hardened so we wont use this method. |
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# Second, try stealing the (unused under PaX) PT_GNU_STACK header |
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# We're working on a new utiity to try to do the same safely. See |
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paxctl -qc${flags} "${f}" && continue |
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# http://git.overlays.gentoo.org/gitweb/?p=proj/elfix.git;a=summary |
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# Third, creating a PT_PAX header (works on ET_EXEC) |
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# |
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paxctl -qC${flags} "${f}" && continue |
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# Fourth - check if it loads to 0 (probably an ET_DYN) and if so, |
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pt_fail=1 |
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# try rebasing with prelink first to give paxctl some space to |
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pt_failures="${pt_failures} ${f}" |
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# grow downwards into. |
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done |
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#if type -p objdump > /dev/null && type -p prelink > /dev/null; then |
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# zero_load_alignment=$(objdump -p "${f}" | \ |
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#Next try paxctl-ng -> this will not create/convert any program headers |
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# grep -E '^[[:space:]]*LOAD[[:space:]]*off[[:space:]]*0x0+[[:space:]]' | \ |
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elif type -p paxctl-ng > /dev/null && paxctl-ng -L ; then |
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# sed -e 's/.*align\(.*\)/\1/') |
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einfo "PT PaX marking -${flags} with paxctl-ng" |
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# if [[ ${zero_load_alignment} != "" ]]; then |
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flags="${flags//z}" |
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# prelink -r $(( 2*(${zero_load_alignment}) )) && |
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_pax_list_files einfo "$@" |
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# paxctl -qC${flags} "${f}" && continue |
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for f in "$@"; do |
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# fi |
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[[ ${dodefault} == "yes" ]] && paxctl-ng -L -z "${f}" |
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#fi |
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[ "${flags}" ] || continue |
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fail=1 |
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paxctl-ng -L -${flags} "${f}" && continue |
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failures="${failures} ${f}" |
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pt_fail=1 |
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done |
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pt_failures="${pt_failures} ${f}" |
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elif type -p scanelf > /dev/null && [[ ${PAX_MARKINGS} != "none" ]]; then |
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done |
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# Try scanelf, the Gentoo swiss-army knife ELF utility |
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# Currently this sets PT if it can, no option to control what it does. |
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#Finally fall back on scanelf |
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einfo "Fallback PaX marking -${flags}" |
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elif type -p scanelf > /dev/null && [[ ${PAX_MARKINGS} != "none" ]]; then |
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_pax_list_files einfo "$@" |
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einfo "Fallback PaX marking -${flags} with scanelf" |
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scanelf -Xxz ${flags} "$@" |
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_pax_list_files einfo "$@" |
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elif [[ ${PAX_MARKINGS} != "none" ]]; then |
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scanelf -Xxz ${flags} "$@" |
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# Out of options! |
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failures="$*" |
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#We failed to set PT_PAX flags |
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fail=1 |
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elif [[ ${PAX_MARKINGS} != "none" ]]; then |
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pt_failures="$*" |
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pt_fail=1 |
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fi |
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if [[ ${pt_fail} == 1 ]]; then |
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ewarn "Failed to set XT_PAX markings -${flags} for:" |
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_pax_list_files ewarn ${pt_failures} |
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ret=1 |
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fi |
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fi |
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fi |
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if [[ ${fail} == 1 ]]; then |
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ewarn "Failed to set PaX markings -${flags} for:" |
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if has XT ${PAX_MARKINGS}; then |
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_pax_list_files ewarn ${failures} |
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ewarn "Executables may be killed by PaX kernels." |
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flags="${flags//z}" |
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#First try paxctl-ng |
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if type -p paxctl-ng > /dev/null && paxctl-ng -l ; then |
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einfo "XT PaX marking -${flags} with paxctl-ng" |
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_pax_list_files einfo "$@" |
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for f in "$@"; do |
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[[ ${dodefault} == "yes" ]] && paxctl-ng -d "${f}" |
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[ "${flags}" ] || continue |
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paxctl-ng -l -${flags} "${f}" && continue |
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xt_fail=1 |
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xt_failures="${tx_failures} ${f}" |
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done |
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#Next try setfattr |
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elif type -p setfattr > /dev/null; then |
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[ "${flags//[!Ee]}" ] || flags+="e" # bug 447150 |
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einfo "XT PaX marking -${flags} with setfattr" |
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_pax_list_files einfo "$@" |
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for f in "$@"; do |
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[[ ${dodefault} == "yes" ]] && setfattr -x "user.pax.flags" "${f}" |
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setfattr -n "user.pax.flags" -v "${flags}" "${f}" && continue |
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xt_fail=1 |
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xt_failures="${tx_failures} ${f}" |
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done |
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#We failed to set PT_PAX flags |
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elif [[ ${PAX_MARKINGS} != "none" ]]; then |
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pt_failures="$*" |
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pt_fail=1 |
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fi |
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if [[ ${xt_fail} == 1 ]]; then |
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ewarn "Failed to set XT_PAX markings -${flags} for:" |
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_pax_list_files ewarn ${xt_failures} |
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ret=1 |
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fi |
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fi |
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fi |
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return ${fail} |
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[[ ${ret} == 1 ]] && ewarn "Executables may be killed by PaX kernels." |
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return ${ret} |
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} |
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} |
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# @FUNCTION: list-paxables |
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# @FUNCTION: list-paxables |
