commit: 78e50f251c0ad49437a4146dc2bdd1552a88fe04 Author: Michael Vetter <jubalh <AT> iodoru <DOT> org> AuthorDate: Fri Feb 16 11:22:10 2018 +0000 Commit: Lars Wendler <polynomial-c <AT> gentoo <DOT> org> CommitDate: Sat Feb 17 12:50:11 2018 +0000 URL: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=78e50f25
sys-apps/shadow: Fix CVE-2018-7169 Fix CVE-2018-7169 by applying upstream patch: https://github.com/shadow-maint/shadow/commit/fb28c99b8a66ff2605c5cb96abc0a4d975f92de0 Bug: https://bugs.gentoo.org/647790 Package-Manager: Portage-2.3.19, Repoman-2.3.6 Closes: https://github.com/gentoo/gentoo/pull/7203 .../shadow/files/shadow-4.5-CVE-2018-7169.patch | 180 ++++++++++++++++++ sys-apps/shadow/shadow-4.5-r1.ebuild | 210 +++++++++++++++++++++ 2 files changed, 390 insertions(+) diff --git a/sys-apps/shadow/files/shadow-4.5-CVE-2018-7169.patch b/sys-apps/shadow/files/shadow-4.5-CVE-2018-7169.patch new file mode 100644 index 00000000000..30ad9e61406 --- /dev/null +++ b/sys-apps/shadow/files/shadow-4.5-CVE-2018-7169.patch @@ -0,0 +1,180 @@ +From fb28c99b8a66ff2605c5cb96abc0a4d975f92de0 Mon Sep 17 00:00:00 2001 +From: Aleksa Sarai <[email protected]> +Date: Thu, 15 Feb 2018 23:49:40 +1100 +Subject: [PATCH] newgidmap: enforce setgroups=deny if self-mapping a group + +This is necessary to match the kernel-side policy of "self-mapping in a +user namespace is fine, but you cannot drop groups" -- a policy that was +created in order to stop user namespaces from allowing trivial privilege +escalation by dropping supplementary groups that were "blacklisted" from +certain paths. + +This is the simplest fix for the underlying issue, and effectively makes +it so that unless a user has a valid mapping set in /etc/subgid (which +only administrators can modify) -- and they are currently trying to use +that mapping -- then /proc/$pid/setgroups will be set to deny. This +workaround is only partial, because ideally it should be possible to set +an "allow_setgroups" or "deny_setgroups" flag in /etc/subgid to allow +administrators to further restrict newgidmap(1). + +We also don't write anything in the "allow" case because "allow" is the +default, and users may have already written "deny" even if they +technically are allowed to use setgroups. And we don't write anything if +the setgroups policy is already "deny". + +Ref: https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1729357 +Fixes: CVE-2018-7169 +Reported-by: Craig Furman <[email protected]> +Signed-off-by: Aleksa Sarai <[email protected]> +--- + src/newgidmap.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++------ + 1 file changed, 80 insertions(+), 9 deletions(-) + +diff --git a/src/newgidmap.c b/src/newgidmap.c +index b1e33513..59a2e75c 100644 +--- a/src/newgidmap.c ++++ b/src/newgidmap.c +@@ -46,32 +46,37 @@ + */ + const char *Prog; + +-static bool verify_range(struct passwd *pw, struct map_range *range) ++ ++static bool verify_range(struct passwd *pw, struct map_range *range, bool *allow_setgroups) + { + /* An empty range is invalid */ + if (range->count == 0) + return false; + +- /* Test /etc/subgid */ +- if (have_sub_gids(pw->pw_name, range->lower, range->count)) ++ /* Test /etc/subgid. If the mapping is valid then we allow setgroups. */ ++ if (have_sub_gids(pw->pw_name, range->lower, range->count)) { ++ *allow_setgroups = true; + return true; ++ } + +- /* Allow a process to map its own gid */ +- if ((range->count == 1) && (pw->pw_gid == range->lower)) ++ /* Allow a process to map its own gid. */ ++ if ((range->count == 1) && (pw->pw_gid == range->lower)) { ++ /* noop -- if setgroups is enabled already we won't disable it. */ + return true; ++ } + + return false; + } + + static void verify_ranges(struct passwd *pw, int ranges, +- struct map_range *mappings) ++ struct map_range *mappings, bool *allow_setgroups) + { + struct map_range *mapping; + int idx; + + mapping = mappings; + for (idx = 0; idx < ranges; idx++, mapping++) { +- if (!verify_range(pw, mapping)) { ++ if (!verify_range(pw, mapping, allow_setgroups)) { + fprintf(stderr, _( "%s: gid range [%lu-%lu) -> [%lu-%lu) not allowed\n"), + Prog, + mapping->upper, +@@ -89,6 +94,70 @@ static void usage(void) + exit(EXIT_FAILURE); + } + ++void write_setgroups(int proc_dir_fd, bool allow_setgroups) ++{ ++ int setgroups_fd; ++ char *policy, policy_buffer[4096]; ++ ++ /* ++ * Default is "deny", and any "allow" will out-rank a "deny". We don't ++ * forcefully write an "allow" here because the process we are writing ++ * mappings for may have already set themselves to "deny" (and "allow" ++ * is the default anyway). So allow_setgroups == true is a noop. ++ */ ++ policy = "deny\n"; ++ if (allow_setgroups) ++ return; ++ ++ setgroups_fd = openat(proc_dir_fd, "setgroups", O_RDWR|O_CLOEXEC); ++ if (setgroups_fd < 0) { ++ /* ++ * If it's an ENOENT then we are on too old a kernel for the setgroups ++ * code to exist. Emit a warning and bail on this. ++ */ ++ if (ENOENT == errno) { ++ fprintf(stderr, _("%s: kernel doesn't support setgroups restrictions\n"), Prog); ++ goto out; ++ } ++ fprintf(stderr, _("%s: couldn't open process setgroups: %s\n"), ++ Prog, ++ strerror(errno)); ++ exit(EXIT_FAILURE); ++ } ++ ++ /* ++ * Check whether the policy is already what we want. /proc/self/setgroups ++ * is write-once, so attempting to write after it's already written to will ++ * fail. ++ */ ++ if (read(setgroups_fd, policy_buffer, sizeof(policy_buffer)) < 0) { ++ fprintf(stderr, _("%s: failed to read setgroups: %s\n"), ++ Prog, ++ strerror(errno)); ++ exit(EXIT_FAILURE); ++ } ++ if (!strncmp(policy_buffer, policy, strlen(policy))) ++ goto out; ++ ++ /* Write the policy. */ ++ if (lseek(setgroups_fd, 0, SEEK_SET) < 0) { ++ fprintf(stderr, _("%s: failed to seek setgroups: %s\n"), ++ Prog, ++ strerror(errno)); ++ exit(EXIT_FAILURE); ++ } ++ if (dprintf(setgroups_fd, "%s", policy) < 0) { ++ fprintf(stderr, _("%s: failed to setgroups %s policy: %s\n"), ++ Prog, ++ policy, ++ strerror(errno)); ++ exit(EXIT_FAILURE); ++ } ++ ++out: ++ close(setgroups_fd); ++} ++ + /* + * newgidmap - Set the gid_map for the specified process + */ +@@ -103,6 +172,7 @@ int main(int argc, char **argv) + struct stat st; + struct passwd *pw; + int written; ++ bool allow_setgroups = false; + + Prog = Basename (argv[0]); + +@@ -145,7 +215,7 @@ int main(int argc, char **argv) + (unsigned long) getuid ())); + return EXIT_FAILURE; + } +- ++ + /* Get the effective uid and effective gid of the target process */ + if (fstat(proc_dir_fd, &st) < 0) { + fprintf(stderr, _("%s: Could not stat directory for target %u\n"), +@@ -177,8 +247,9 @@ int main(int argc, char **argv) + if (!mappings) + usage(); + +- verify_ranges(pw, ranges, mappings); ++ verify_ranges(pw, ranges, mappings, &allow_setgroups); + ++ write_setgroups(proc_dir_fd, allow_setgroups); + write_mapping(proc_dir_fd, ranges, mappings, "gid_map"); + sub_gid_close(); + diff --git a/sys-apps/shadow/shadow-4.5-r1.ebuild b/sys-apps/shadow/shadow-4.5-r1.ebuild new file mode 100644 index 00000000000..f13b863620e --- /dev/null +++ b/sys-apps/shadow/shadow-4.5-r1.ebuild @@ -0,0 +1,210 @@ +# Copyright 1999-2018 Gentoo Foundation +# Distributed under the terms of the GNU General Public License v2 + +EAPI="5" + +inherit eutils libtool pam multilib + +DESCRIPTION="Utilities to deal with user accounts" +HOMEPAGE="https://github.com/shadow-maint/shadow http://pkg-shadow.alioth.debian.org/"; +SRC_URI="https://github.com/shadow-maint/shadow/releases/download/${PV}/${P}.tar.gz"; + +LICENSE="BSD GPL-2" +SLOT="0" +KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86" +IUSE="acl audit +cracklib nls pam selinux skey xattr" +# Taken from the man/Makefile.am file. +LANGS=( cs da de es fi fr hu id it ja ko pl pt_BR ru sv tr zh_CN zh_TW ) + +RDEPEND="acl? ( sys-apps/acl:0= ) + audit? ( >=sys-process/audit-2.6:0= ) + cracklib? ( >=sys-libs/cracklib-2.7-r3:0= ) + pam? ( virtual/pam:0= ) + skey? ( sys-auth/skey:0= ) + selinux? ( + >=sys-libs/libselinux-1.28:0= + sys-libs/libsemanage:0= + ) + nls? ( virtual/libintl ) + xattr? ( sys-apps/attr:0= )" +DEPEND="${RDEPEND} + app-arch/xz-utils + nls? ( sys-devel/gettext )" +RDEPEND="${RDEPEND} + pam? ( >=sys-auth/pambase-20150213 )" + +PATCHES=( + "${FILESDIR}/${PN}-4.1.3-dots-in-usernames.patch" + "${FILESDIR}/${P}-CVE-2018-7169.patch" +) + +src_prepare() { + epatch "${PATCHES[@]}" + epatch_user + #eautoreconf + elibtoolize +} + +src_configure() { + econf \ + --without-group-name-max-length \ + --without-tcb \ + --enable-shared=no \ + --enable-static=yes \ + $(use_with acl) \ + $(use_with audit) \ + $(use_with cracklib libcrack) \ + $(use_with pam libpam) \ + $(use_with skey) \ + $(use_with selinux) \ + $(use_enable nls) \ + $(use_with elibc_glibc nscd) \ + $(use_with xattr attr) + has_version 'sys-libs/uclibc[-rpc]' && sed -i '/RLOGIN/d' config.h #425052 + + if use nls ; then + local l langs="po" # These are the pot files. + for l in ${LANGS[*]} ; do + has ${l} ${LINGUAS-${l}} && langs+=" ${l}" + done + sed -i "/^SUBDIRS = /s:=.*:= ${langs}:" man/Makefile || die + fi +} + +set_login_opt() { + local comment="" opt=$1 val=$2 + if [[ -z ${val} ]]; then + comment="#" + sed -i \ + -e "/^${opt}\>/s:^:#:" \ + "${ED}"/etc/login.defs || die + else + sed -i -r \ + -e "/^#?${opt}\>/s:.*:${opt} ${val}:" \ + "${ED}"/etc/login.defs + fi + local res=$(grep "^${comment}${opt}\>" "${ED}"/etc/login.defs) + einfo "${res:-Unable to find ${opt} in /etc/login.defs}" +} + +src_install() { + emake DESTDIR="${D}" suidperms=4711 install + + # Remove libshadow and libmisc; see bug 37725 and the following + # comment from shadow's README.linux: + # Currently, libshadow.a is for internal use only, so if you see + # -lshadow in a Makefile of some other package, it is safe to + # remove it. + rm -f "${ED}"/{,usr/}$(get_libdir)/lib{misc,shadow}.{a,la} + + insinto /etc + if ! use pam ; then + insopts -m0600 + doins etc/login.access etc/limits + fi + + # needed for 'useradd -D' + insinto /etc/default + insopts -m0600 + doins "${FILESDIR}"/default/useradd + + # move passwd to / to help recover broke systems #64441 + mv "${ED}"/usr/bin/passwd "${ED}"/bin/ || die + dosym /bin/passwd /usr/bin/passwd + + cd "${S}" + insinto /etc + insopts -m0644 + newins etc/login.defs login.defs + + set_login_opt CREATE_HOME yes + if ! use pam ; then + set_login_opt MAIL_CHECK_ENAB no + set_login_opt SU_WHEEL_ONLY yes + set_login_opt CRACKLIB_DICTPATH /usr/$(get_libdir)/cracklib_dict + set_login_opt LOGIN_RETRIES 3 + set_login_opt ENCRYPT_METHOD SHA512 + set_login_opt CONSOLE + else + dopamd "${FILESDIR}"/pam.d-include/shadow + + for x in chpasswd chgpasswd newusers; do + newpamd "${FILESDIR}"/pam.d-include/passwd ${x} + done + + for x in chage chsh chfn \ + user{add,del,mod} group{add,del,mod} ; do + newpamd "${FILESDIR}"/pam.d-include/shadow ${x} + done + + # comment out login.defs options that pam hates + local opt sed_args=() + for opt in \ + CHFN_AUTH \ + CONSOLE \ + CRACKLIB_DICTPATH \ + ENV_HZ \ + ENVIRON_FILE \ + FAILLOG_ENAB \ + FTMP_FILE \ + LASTLOG_ENAB \ + MAIL_CHECK_ENAB \ + MOTD_FILE \ + NOLOGINS_FILE \ + OBSCURE_CHECKS_ENAB \ + PASS_ALWAYS_WARN \ + PASS_CHANGE_TRIES \ + PASS_MIN_LEN \ + PORTTIME_CHECKS_ENAB \ + QUOTAS_ENAB \ + SU_WHEEL_ONLY + do + set_login_opt ${opt} + sed_args+=( -e "/^#${opt}\>/b pamnote" ) + done + sed -i "${sed_args[@]}" \ + -e 'b exit' \ + -e ': pamnote; i# NOTE: This setting should be configured via /etc/pam.d/ and not in this file.' \ + -e ': exit' \ + "${ED}"/etc/login.defs || die + + # remove manpages that pam will install for us + # and/or don't apply when using pam + find "${ED}"/usr/share/man \ + '(' -name 'limits.5*' -o -name 'suauth.5*' ')' \ + -delete + + # Remove pam.d files provided by pambase. + rm "${ED}"/etc/pam.d/{login,passwd,su} || die + fi + + # Remove manpages that are handled by other packages + find "${ED}"/usr/share/man \ + '(' -name id.1 -o -name passwd.5 -o -name getspnam.3 ')' \ + -delete + + cd "${S}" + dodoc ChangeLog NEWS TODO + newdoc README README.download + cd doc + dodoc HOWTO README* WISHLIST *.txt +} + +pkg_preinst() { + rm -f "${EROOT}"/etc/pam.d/system-auth.new \ + "${EROOT}/etc/login.defs.new" +} + +pkg_postinst() { + # Enable shadow groups. + if [ ! -f "${EROOT}"/etc/gshadow ] ; then + if grpck -r -R "${EROOT}" 2>/dev/null ; then + grpconv -R "${EROOT}" + else + ewarn "Running 'grpck' returned errors. Please run it by hand, and then" + ewarn "run 'grpconv' afterwards!" + fi + fi + + einfo "The 'adduser' symlink to 'useradd' has been dropped." +}
