From 2ea9cbefb8e0923f2f58e7e8022f3e134977a87a Mon Sep 17 00:00:00 2001 From: Scott Murray Date: Mon, 25 Jul 2022 14:23:13 -0400 Subject: Add SELinux feature Add agl-selinux feature to enable SELinux support. Notes: - SELinux is in permissive mode by default for now, and using the targeted policy by default. - The linux-yocto specific bbappend in meta-selinux is masked out in favor of adding a more universal kernel configuration fragment with AGL's own scheme. - SELinux specific recipes and bbappends are added via a meta-selinux dynamic-layers addition in meta-agl-core to keep using meta-selinux optional. This will avoid issues with the Yocto autobuilder testing of meta-agl-core. - To avoid the effectively hard-coded autorelabel on first boot, a bbappend is added to the selinux-autorelabel recipe to remove the flag creation. In the off chance that a build happens on a filesystem without xattr support, the logic in the selinux-image bbclass will still touch the /.autorelabel flag and trigger relabeling. - A systemd unit and script are added with a new systemd-selinux-relabel recipe to handle relabeling of some systemd generated files that do not get handled during root filesystem construction. Some of these can be addressed by some upstream tweaks, but /etc/machine-id will always need special handling unless there is a shift to using read-only or stateless root by default. With this workaround we still avoid doing a full relabel and reboot on first boot, which helps simplify CI. Bug-AGL: SPEC-4332 Signed-off-by: Scott Murray Change-Id: Ibf469e11eb3a67709074cc6794b3d12cd5071a90 Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/27790 Tested-by: Jenkins Job builder account ci-image-build: Jenkins Job builder account ci-image-boot-test: Jenkins Job builder account Reviewed-by: Jan-Simon Moeller --- .../systemd/files/systemd-selinux-relabel.service | 12 +++++ .../systemd/files/systemd-selinux-relabel.sh | 12 +++++ .../systemd/systemd-selinux-relabel_1.0.bb | 25 ++++++++++ .../packagegroups/packagegroup-agl-core-selinux.bb | 57 ++++++++++++++++++++++ .../selinux-autorelabel_0.1.bbappend | 1 + .../selinux-autorelabel_aglcore.inc | 4 ++ 6 files changed, 111 insertions(+) create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.service create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.sh create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/systemd-selinux-relabel_1.0.bb create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-platform/packagegroups/packagegroup-agl-core-selinux.bb create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_0.1.bbappend create mode 100644 meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_aglcore.inc (limited to 'meta-agl-core/dynamic-layers/meta-selinux') diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.service b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.service new file mode 100644 index 000000000..b8d394068 --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.service @@ -0,0 +1,12 @@ +[Unit] +Description=Generated file SELinux relabeling +DefaultDependencies=no +After=local-fs.target systemd-machine-id-commit.service +Before=sysinit.target + +[Service] +Type=oneshot +ExecStart=/usr/sbin/systemd-selinux-relabel.sh + +[Install] +WantedBy=sysinit.target diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.sh b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.sh new file mode 100644 index 000000000..b2557a8d6 --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/files/systemd-selinux-relabel.sh @@ -0,0 +1,12 @@ +#!/bin/sh + +# Update labels on files generated on first boot. +/usr/sbin/restorecon -FRi /etc/systemd /etc/machine-id +if [ $? -eq 0 ]; then + # Disable parent service + # NOTE: The service does not use the first boot functionality + # in systemd as /etc/machine-id is not writeable until + # after it is complete. + systemctl disable systemd-selinux-relabel.service +fi +exit 0 diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/systemd-selinux-relabel_1.0.bb b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/systemd-selinux-relabel_1.0.bb new file mode 100644 index 000000000..7e4f9783c --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-core/systemd/systemd-selinux-relabel_1.0.bb @@ -0,0 +1,25 @@ +SUMMARY = "System unit to relabel systemd generated files" +LICENSE = "MIT" +LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302" + +SRC_URI = "file://systemd-selinux-relabel.service \ + file://systemd-selinux-relabel.sh \ +" + +inherit systemd allarch features_check + +SYSTEMD_SERVICE:${PN} = "${BPN}.service" + +REQUIRED_DISTRO_FEATURES = "systemd" + +do_configure[noexec] = "1" +do_compile[noexec] = "1" + +do_install() { + install -d ${D}${systemd_system_unitdir} + install -m 0644 ${WORKDIR}/systemd-selinux-relabel.service ${D}${systemd_system_unitdir}/ + install -d ${D}${sbindir} + install -m 0755 ${WORKDIR}/systemd-selinux-relabel.sh ${D}${sbindir}/ +} + +FILES:${PN} += "${systemd_system_unitdir}" diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-platform/packagegroups/packagegroup-agl-core-selinux.bb b/meta-agl-core/dynamic-layers/meta-selinux/recipes-platform/packagegroups/packagegroup-agl-core-selinux.bb new file mode 100644 index 000000000..493a46f25 --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-platform/packagegroups/packagegroup-agl-core-selinux.bb @@ -0,0 +1,57 @@ +SUMMARY = "SELinux packages" +DESCRIPTION = "SELinux packages required for AGL" +LICENSE = "MIT" + +inherit packagegroup features_check + +REQUIRED_DISTRO_FEATURES = "selinux" + +PACKAGES = " \ + packagegroup-agl-core-selinux \ + packagegroup-agl-core-selinux-devel \ +" + +# +# meta-selinux's packagegroup-core-selinux includes a lot of +# policy development tools with its inclusion of the layer's +# packagegroup-selinux-policycoreutils, which is not really +# desirable for a production image. Create our own base +# packagegroup and an accompanying devel packagegroup that +# agl-devel can trigger pulling in. +# +# NOTES: +# - It seems likely we will always want auditd, so include +# it in the base packagegroup. +# - selinux-autorelabel seems required to handle both the +# edge case of builds done on non-xattr capable filesystems, +# and to allow driving relabeling after potential package +# installation during runtime. +# - packagegroup-selinux-policycoreutils includes a lot of +# things that seem not useful in a lot of systems (e.g. +# the gtk dependent selinux-gui), so for now the devel +# packagegroup aims to include a more minimal set of tools +# aimed at enabling checkpolicy and audit2allow use. +# - Some thought needs to go into whether the relabeling +# fixup packages should be handled separately, as they +# ideally should not go into images using read-only or +# stateless rootfs, but those are image features so we +# cannot check for them here. +# + +RDEPENDS:${PN} = " \ + packagegroup-selinux-minimal \ + auditd \ + selinux-autorelabel \ + systemd-selinux-relabel \ +" + +RDEPENDS:${PN}-devel = " \ + ${BPN} \ + libsepol-bin \ + checkpolicy \ + policycoreutils-loadpolicy \ + policycoreutils-setsebool \ + policycoreutils-hll \ + semodule-utils-semodule-package \ + selinux-python-audit2allow \ +" diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_0.1.bbappend b/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_0.1.bbappend new file mode 100644 index 000000000..793b049e5 --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_0.1.bbappend @@ -0,0 +1 @@ +require ${@bb.utils.contains('AGL_FEATURES', 'aglcore', 'selinux-autorelabel_aglcore.inc', '', d)} diff --git a/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_aglcore.inc b/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_aglcore.inc new file mode 100644 index 000000000..67d3843f4 --- /dev/null +++ b/meta-agl-core/dynamic-layers/meta-selinux/recipes-security/selinux-scripts/selinux-autorelabel_aglcore.inc @@ -0,0 +1,4 @@ +do_install:append() { + # Do not force auto relabeling just from the package getting installed + rm -f ${D}/.autorelabel +} -- cgit 1.2.3-korg