Gentoo Archives: gentoo-dev

From: Sergei Trofimovich <slyfox@g.o>
To: gentoo-dev@l.g.o
Cc: Sergei Trofimovich <slyfox@g.o>, hardened@g.o
Subject: [gentoo-dev] [PATCH] pax-utils.eclass: allow EAPI=8
Date: Thu, 15 Jul 2021 09:59:02
Message-Id: 20210715095817.2603762-1-slyfox@gentoo.org
1 CC: hardened@g.o
2 Closes: https://bugs.gentoo.org/802258
3 Signed-off-by: Sergei Trofimovich <slyfox@g.o>
4 ---
5 eclass/pax-utils.eclass | 4 ++--
6 1 file changed, 2 insertions(+), 2 deletions(-)
7
8 diff --git a/eclass/pax-utils.eclass b/eclass/pax-utils.eclass
9 index 9c4903d24b6..f48dcdafe01 100644
10 --- a/eclass/pax-utils.eclass
11 +++ b/eclass/pax-utils.eclass
12 @@ -1,200 +1,200 @@
13 # Copyright 1999-2021 Gentoo Authors
14 # Distributed under the terms of the GNU General Public License v2
15
16 # @ECLASS: pax-utils.eclass
17 # @MAINTAINER:
18 # The Gentoo Linux Hardened Team <hardened@g.o>
19 # @AUTHOR:
20 # Author: Kevin F. Quinn <kevquinn@g.o>
21 # Author: Anthony G. Basile <blueness@g.o>
22 -# @SUPPORTED_EAPIS: 5 6 7
23 +# @SUPPORTED_EAPIS: 5 6 7 8
24 # @BLURB: functions to provide PaX markings for hardened kernels
25 # @DESCRIPTION:
26 #
27 # This eclass provides support for manipulating PaX markings on ELF binaries,
28 # whether the system is using legacy PT_PAX markings or the newer XATTR_PAX.
29 # The eclass wraps the use of paxctl-ng, paxctl, set/getattr and scanelf utilities,
30 # deciding which to use depending on what's installed on the build host, and
31 # whether we're working with PT_PAX, XATTR_PAX or both.
32 # Legacy PT_PAX markings no longer supported.
33 #
34 # To control what markings are made, set PAX_MARKINGS in /etc/portage/make.conf
35 # to contain either "PT", "XT" or "none". The default is none
36
37 case ${EAPI:-0} in
38 - [567]) ;;
39 + 5|6|7|8) ;;
40 *) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
41 esac
42
43 if [[ -z ${_PAX_UTILS_ECLASS} ]]; then
44 _PAX_UTILS_ECLASS=1
45
46 # @ECLASS-VARIABLE: PAX_MARKINGS
47 # @DESCRIPTION:
48 # Control which markings are made:
49 # PT = PT_PAX markings, XT = XATTR_PAX markings
50 # Default to none markings.
51 PAX_MARKINGS=${PAX_MARKINGS:="none"}
52
53 # @FUNCTION: pax-mark
54 # @USAGE: <flags> <ELF files>
55 # @RETURN: Shell true if we succeed, shell false otherwise
56 # @DESCRIPTION:
57 # Marks <ELF files> with provided PaX <flags>
58 #
59 # Flags are passed directly to the utilities unchanged.
60 #
61 # @CODE
62 # p: disable PAGEEXEC P: enable PAGEEXEC
63 # e: disable EMUTRAMP E: enable EMUTRAMP
64 # m: disable MPROTECT M: enable MPROTECT
65 # r: disable RANDMMAP R: enable RANDMMAP
66 # s: disable SEGMEXEC S: enable SEGMEXEC
67 # @CODE
68 #
69 # Default flags are 'PeMRS', which are the most restrictive settings. Refer
70 # to https://pax.grsecurity.net/ for details on what these flags are all about.
71 #
72 # Please confirm any relaxation of restrictions with the Gentoo Hardened team.
73 # Either ask on the gentoo-hardened mailing list, or CC/assign
74 # hardened@g.o on the bug report.
75 pax-mark() {
76 local f # loop over paxables
77 local flags # pax flags
78 local ret=0 # overall return code of this function
79
80 # Only the actual PaX flags and z are accepted
81 # 1. The leading '-' is optional
82 # 2. -C -c only make sense for paxctl, but are unnecessary
83 # because we progressively do -q -qc -qC
84 # 3. z is allowed for the default
85
86 flags="${1//[!zPpEeMmRrSs]}"
87 [[ "${flags}" ]] || return 0
88 shift
89
90 # z = default. For XATTR_PAX, the default is no xattr field at all
91 local dodefault=""
92 [[ "${flags//[!z]}" ]] && dodefault="yes"
93
94 if has PT ${PAX_MARKINGS}; then
95 # Uncomment to list all files to be marked
96 # _pax_list_files einfo "$@"
97 for f in "$@"; do
98
99 # First try paxctl
100 if type -p paxctl >/dev/null; then
101 einfo "PT_PAX marking -${flags} ${f} with paxctl"
102 # We try modifying the existing PT_PAX_FLAGS header.
103 paxctl -q${flags} "${f}" >/dev/null 2>&1 && continue
104 # We no longer try to create/convert a PT_PAX_FLAGS header, bug #590422
105 # paxctl -qC${flags} "${f}" >/dev/null 2>&1 && continue
106 # paxctl -qc${flags} "${f}" >/dev/null 2>&1 && continue
107 fi
108
109 # Next try paxctl-ng -> this will not create/convert any program headers.
110 if type -p paxctl-ng >/dev/null && paxctl-ng -L ; then
111 einfo "PT_PAX marking -${flags} ${f} with paxctl-ng"
112 flags="${flags//z}"
113 [[ ${dodefault} == "yes" ]] && paxctl-ng -L -z "${f}" >/dev/null 2>&1
114 [[ "${flags}" ]] || continue
115 paxctl-ng -L -${flags} "${f}" >/dev/null 2>&1 && continue
116 fi
117
118 # Finally fall back on scanelf.
119 if type -p scanelf >/dev/null && [[ ${PAX_MARKINGS} != "none" ]]; then
120 einfo "PT_PAX marking -${flags} ${f} with scanelf"
121 scanelf -Xxz ${flags} "$f" >/dev/null 2>&1
122 # We failed to set PT_PAX flags.
123 elif [[ ${PAX_MARKINGS} != "none" ]]; then
124 elog "Failed to set PT_PAX markings -${flags} ${f}."
125 ret=1
126 fi
127 done
128 fi
129
130 if has XT ${PAX_MARKINGS}; then
131 # Uncomment to list all files to be marked
132 # _pax_list_files einfo "$@"
133 flags="${flags//z}"
134 for f in "$@"; do
135
136 # First try paxctl-ng.
137 if type -p paxctl-ng >/dev/null && paxctl-ng -l ; then
138 einfo "XATTR_PAX marking -${flags} ${f} with paxctl-ng"
139 [[ ${dodefault} == "yes" ]] && paxctl-ng -d "${f}" >/dev/null 2>&1
140 [[ "${flags}" ]] || continue
141 paxctl-ng -l -${flags} "${f}" >/dev/null 2>&1 && continue
142 fi
143
144 # Next try setfattr.
145 if type -p setfattr >/dev/null; then
146 [[ "${flags//[!Ee]}" ]] || flags+="e" # bug 447150
147 einfo "XATTR_PAX marking -${flags} ${f} with setfattr"
148 [[ ${dodefault} == "yes" ]] && setfattr -x "user.pax.flags" "${f}" >/dev/null 2>&1
149 setfattr -n "user.pax.flags" -v "${flags}" "${f}" >/dev/null 2>&1 && continue
150 fi
151
152 # We failed to set XATTR_PAX flags.
153 if [[ ${PAX_MARKINGS} != "none" ]]; then
154 elog "Failed to set XATTR_PAX markings -${flags} ${f}."
155 ret=1
156 fi
157 done
158 fi
159
160 # [[ ${ret} == 1 ]] && elog "Executables may be killed by PaX kernels."
161
162 return ${ret}
163 }
164
165 # @FUNCTION: list-paxables
166 # @USAGE: <files>
167 # @RETURN: Subset of <files> which are ELF executables or shared objects
168 # @DESCRIPTION:
169 # Print to stdout all of the <files> that are suitable to have PaX flag
170 # markings, i.e., filter out the ELF executables or shared objects from a list
171 # of files. This is useful for passing wild-card lists to pax-mark, although
172 # in general it is preferable for ebuilds to list precisely which ELFS are to
173 # be marked. Often not all the ELF installed by a package need remarking.
174 # @EXAMPLE:
175 # pax-mark -m $(list-paxables ${S}/{,usr/}bin/*)
176 list-paxables() {
177 file "$@" 2> /dev/null | grep -E 'ELF.*(executable|shared object)' | sed -e 's/: .*$//'
178 }
179
180 # @FUNCTION: host-is-pax
181 # @RETURN: Shell true if the build process is PaX enabled, shell false otherwise
182 # @DESCRIPTION:
183 # This is intended for use where the build process must be modified conditionally
184 # depending on whether the host is PaX enabled or not. It is not indented to
185 # determine whether the final binaries need PaX markings. Note: if procfs is
186 # not mounted on /proc, this returns shell false (e.g. Gentoo/FreeBSD).
187 host-is-pax() {
188 grep -qs ^PaX: /proc/self/status
189 }
190
191
192 # INTERNAL FUNCTIONS
193 # ------------------
194 #
195 # These functions are for use internally by the eclass - do not use
196 # them elsewhere as they are not supported (i.e. they may be removed
197 # or their function may change arbitrarily).
198
199 # @FUNCTION: _pax_list_files
200 # @INTERNAL
201 # @USAGE: <command to display items> [items]
202 # @DESCRIPTION:
203 # Display a list of things, one per line, indented a bit, using the
204 # display command in $1.
205 _pax_list_files() {
206 local f cmd
207 cmd=$1
208 shift
209 for f in "$@"; do
210 ${cmd} " ${f}"
211 done
212 }
213
214 fi
215 --
216 2.32.0

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[gentoo-dev] Re: [PATCH] pax-utils.eclass: allow EAPI=8 Sergei Trofimovich <slyfox@g.o>