Files
poky/meta/recipes-extended/shadow/shadow.inc
Jagadeesh Krishnanjanappa f183e88d06 shadow: CVE-2018-7169
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

Affects shadow <= 4.5

(From OE-Core rev: a875522540372a4fa6658885692e564dfd729f54)

Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2018-08-29 15:23:51 +01:00

207 lines
7.6 KiB
PHP

SUMMARY = "Tools to change and administer password and group data"
HOMEPAGE = "http://pkg-shadow.alioth.debian.org"
BUGTRACKER = "https://alioth.debian.org/tracker/?group_id=30580"
SECTION = "base/utils"
LICENSE = "BSD | Artistic-1.0"
LIC_FILES_CHKSUM = "file://COPYING;md5=ed80ff1c2b40843cf5768e5229cf16e5 \
file://src/passwd.c;beginline=8;endline=30;md5=d83888ea14ae61951982d77125947661"
DEPENDS = "virtual/crypt"
UPSTREAM_CHECK_URI = "https://github.com/shadow-maint/shadow/releases"
SRC_URI = "https://downloads.yoctoproject.org/mirror/sources/${BP}.tar.xz \
file://shadow-4.1.3-dots-in-usernames.patch \
file://usermod-fix-compilation-failure-with-subids-disabled.patch \
file://fix-installation-failure-with-subids-disabled.patch \
file://0001-Do-not-read-login.defs-before-doing-chroot.patch \
file://check_size_of_uid_t_and_gid_t_using_AC_CHECK_SIZEOF.patch \
file://0001-useradd-copy-extended-attributes-of-home.patch \
file://0001-shadow-CVE-2017-12424 \
file://CVE-2017-2616.patch \
${@bb.utils.contains('PACKAGECONFIG', 'pam', '${PAM_SRC_URI}', '', d)} \
file://CVE-2018-7169.patch \
"
SRC_URI_append_class-target = " \
file://login_defs_pam.sed \
file://shadow-update-pam-conf.patch \
file://shadow-relaxed-usernames.patch \
"
SRC_URI_append_class-native = " \
file://0001-Disable-use-of-syslog-for-sysroot.patch \
file://allow-for-setting-password-in-clear-text.patch \
file://commonio.c-fix-unexpected-open-failure-in-chroot-env.patch \
file://0001-useradd.c-create-parent-directories-when-necessary.patch \
"
SRC_URI_append_class-nativesdk = " \
file://0001-Disable-use-of-syslog-for-sysroot.patch \
"
SRC_URI[md5sum] = "2bfafe7d4962682d31b5eba65dba4fc8"
SRC_URI[sha256sum] = "3b0893d1476766868cd88920f4f1231c4795652aa407569faff802bcda0f3d41"
# Additional Policy files for PAM
PAM_SRC_URI = "file://pam.d/chfn \
file://pam.d/chpasswd \
file://pam.d/chsh \
file://pam.d/login \
file://pam.d/newusers \
file://pam.d/passwd \
file://pam.d/su"
inherit autotools gettext
EXTRA_OECONF += "--without-audit \
--without-libcrack \
--without-selinux \
--with-group-name-max-length=24 \
--enable-subordinate-ids=yes \
${NSCDOPT}"
NSCDOPT = ""
NSCDOPT_class-native = "--without-nscd"
NSCDOPT_class-nativesdk = "--without-nscd"
NSCDOPT_libc-glibc = "${@bb.utils.contains('DISTRO_FEATURES', 'libc-spawn', '--with-nscd', '--without-nscd', d)}"
PAM_PLUGINS = "libpam-runtime \
pam-plugin-faildelay \
pam-plugin-securetty \
pam-plugin-nologin \
pam-plugin-env \
pam-plugin-group \
pam-plugin-limits \
pam-plugin-lastlog \
pam-plugin-motd \
pam-plugin-mail \
pam-plugin-shells \
pam-plugin-rootok"
PACKAGECONFIG ??= "${@bb.utils.filter('DISTRO_FEATURES', 'pam', d)} \
${@bb.utils.contains('DISTRO_FEATURES', 'xattr', 'attr', '', d)}"
PACKAGECONFIG_class-native ??= "${@bb.utils.contains('DISTRO_FEATURES', 'xattr', 'attr', '', d)}"
PACKAGECONFIG_class-nativesdk = ""
PACKAGECONFIG[pam] = "--with-libpam,--without-libpam,libpam,${PAM_PLUGINS}"
PACKAGECONFIG[attr] = "--with-attr,--without-attr,attr"
PACKAGECONFIG[acl] = "--with-acl,--without-acl,acl"
RDEPENDS_${PN} = "shadow-securetty \
base-passwd \
util-linux-sulogin"
RDEPENDS_${PN}_class-native = ""
RDEPENDS_${PN}_class-nativesdk = ""
do_install() {
oe_runmake DESTDIR="${D}" sbindir="${base_sbindir}" usbindir="${sbindir}" install
# Info dir listing isn't interesting at this point so remove it if it exists.
if [ -e "${D}${infodir}/dir" ]; then
rm -f ${D}${infodir}/dir
fi
# Enable CREATE_HOME by default.
sed -i 's/#CREATE_HOME/CREATE_HOME/g' ${D}${sysconfdir}/login.defs
# As we are on an embedded system, ensure the users mailbox is in
# ~/ not /var/spool/mail by default, as who knows where or how big
# /var is. The system MDA will set this later anyway.
sed -i 's/MAIL_DIR/#MAIL_DIR/g' ${D}${sysconfdir}/login.defs
sed -i 's/#MAIL_FILE/MAIL_FILE/g' ${D}${sysconfdir}/login.defs
# Disable checking emails.
sed -i 's/MAIL_CHECK_ENAB/#MAIL_CHECK_ENAB/g' ${D}${sysconfdir}/login.defs
# Comment out SU_NAME to work correctly with busybox
# See Bug#5359 and Bug#7173
sed -i 's:^SU_NAME:#SU_NAME:g' ${D}${sysconfdir}/login.defs
# Use proper encryption for passwords
sed -i 's/^#ENCRYPT_METHOD.*$/ENCRYPT_METHOD SHA512/' ${D}${sysconfdir}/login.defs
# Now we don't have a mail system. Disable mail creation for now.
sed -i 's:/bin/bash:/bin/sh:g' ${D}${sysconfdir}/default/useradd
sed -i '/^CREATE_MAIL_SPOOL/ s:^:#:' ${D}${sysconfdir}/default/useradd
# Use users group by default
sed -i 's,^GROUP=1000,GROUP=100,g' ${D}${sysconfdir}/default/useradd
}
do_install_append() {
# Ensure that the image has as a /var/spool/mail dir so shadow can
# put mailboxes there if the user reconfigures shadow to its
# defaults (see sed below).
install -m 0775 -d ${D}${localstatedir}/spool/mail
chown root:mail ${D}${localstatedir}/spool/mail
if [ -e ${WORKDIR}/pam.d ]; then
install -d ${D}${sysconfdir}/pam.d/
install -m 0644 ${WORKDIR}/pam.d/* ${D}${sysconfdir}/pam.d/
# Remove defaults that are not used when supporting PAM.
sed -i -f ${WORKDIR}/login_defs_pam.sed ${D}${sysconfdir}/login.defs
fi
install -d ${D}${sbindir} ${D}${base_sbindir} ${D}${base_bindir}
# Move binaries to the locations we want
rm ${D}${sbindir}/vigr
ln -sf vipw.${BPN} ${D}${base_sbindir}/vigr
if [ "${sbindir}" != "${base_sbindir}" ]; then
mv ${D}${sbindir}/vipw ${D}${base_sbindir}/vipw
fi
if [ "${bindir}" != "${base_bindir}" ]; then
mv ${D}${bindir}/login ${D}${base_bindir}/login
mv ${D}${bindir}/su ${D}${base_bindir}/su
fi
# Handle link properly after rename, otherwise missing files would
# lead rpm failed dependencies.
ln -sf newgrp.${BPN} ${D}${bindir}/sg
}
PACKAGES =+ "${PN}-base"
FILES_${PN}-base = "\
${base_bindir}/login.shadow \
${base_bindir}/su.shadow \
${bindir}/sg \
${bindir}/newgrp.shadow \
${bindir}/groups.shadow \
${sysconfdir}/pam.d/login \
${sysconfdir}/pam.d/su \
${sysconfdir}/login.defs \
"
RDEPENDS_${PN} += "${PN}-base"
inherit update-alternatives
ALTERNATIVE_PRIORITY = "200"
ALTERNATIVE_${PN} = "passwd chfn chsh chpasswd vipw vigr nologin"
ALTERNATIVE_LINK_NAME[chpasswd] = "${sbindir}/chpasswd"
ALTERNATIVE_LINK_NAME[vipw] = "${base_sbindir}/vipw"
ALTERNATIVE_LINK_NAME[vigr] = "${base_sbindir}/vigr"
ALTERNATIVE_LINK_NAME[nologin] = "${base_sbindir}/nologin"
ALTERNATIVE_${PN}-base = "newgrp groups login su"
ALTERNATIVE_LINK_NAME[login] = "${base_bindir}/login"
ALTERNATIVE_LINK_NAME[su] = "${base_bindir}/su"
ALTERNATIVE_${PN}-doc = "passwd.5 getspnam.3 groups.1 su.1 nologin.8"
ALTERNATIVE_LINK_NAME[passwd.5] = "${mandir}/man5/passwd.5"
ALTERNATIVE_LINK_NAME[getspnam.3] = "${mandir}/man3/getspnam.3"
ALTERNATIVE_LINK_NAME[groups.1] = "${mandir}/man1/groups.1"
ALTERNATIVE_LINK_NAME[su.1] = "${mandir}/man1/su.1"
ALTERNATIVE_LINK_NAME[nologin.8] = "${mandir}/man8/nologin.8"
PACKAGE_WRITE_DEPS += "shadow-native"
pkg_postinst_${PN}_class-target () {
if [ "x$D" != "x" ]; then
rootarg="--root $D"
else
rootarg=""
fi
pwconv $rootarg || exit 1
grpconv $rootarg || exit 1
}