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|
#!/bin/bash
if [ ${DIB_DEBUG_TRACE:-1} -gt 0 ]; then
set -x
fi
set -eu
set -o pipefail
# parser isn't smart enough to figure out \
# dib-lint: disable=safe_sudo
# Here be dragons ... a previous dragon slayer helpfully pointed out in
# http://www.spinics.net/lists/selinux/msg17379.html
#
# Not all of the contexts defined by the offline system's
# file_contexts may be valid under the policy of the host on which
# you are running (e.g. if they run different distributions or even
# different releases of the same distribution), which will normally
# prevent setting those contexts (the kernel won't recognize them).
# If you have this issue, you'll need to run setfiles as root in a
# special domain, setfiles_mac_t, that is allowed to set contexts
# unknown to the host policy, and likely chrooted so that it doesn't
# ask the kernel whether the contexts are valid via
# /sys/fs/selinux/context. That is how livecd-creator supported
# creating images for other releases.
# One issue you might see without fixing selinux file labels is sshd
# will run in the kernel_t domain instead of the sshd_t domain, making
# ssh connections fail with "Unable to get valid context for <user>"
# error message. Other failures will occur too.
# XXX: is it really valid to build rpm-distros without this?
if [[ ! -f ${TARGET_ROOT}/etc/selinux/targeted/contexts/files/file_contexts ]]; then
echo "No selinux policy found in chroot, skipping..."
exit 0
fi
if [[ ! -x ${TARGET_ROOT}/usr/sbin/setfiles ]]; then
echo "Can not find setfiles in chroot!"
exit 1
fi
# If we're on a selinux system, enable permissive mode for
# setfiles_mac_t so we can relabel within the chroot without concern
# for whatever policy is in the host kernel. We will run under
# "runcon" to specifically allow this
_runcon=""
if [[ -d /sys/fs/selinux ]] && selinuxenabled; then
sudo semanage permissive -a setfiles_mac_t
_runcon="runcon -t setfiles_mac_t -- "
fi
# setfiles in > Fedora 26 added this flag:
# do not read /proc/mounts to obtain a list of
# non-seclabel mounts to be excluded from relabeling
# checks. Setting this option is useful where there is
# a non-seclabel fs mounted with a seclabel fs
# this describes our situation of being on a loopback device on
# an ubuntu system, say. See also
# https://bugzilla.redhat.com/show_bug.cgi?id=1472709
_dash_m=""
if [[ $DISTRO_NAME == "fedora" && $DIB_RELEASE -ge 26 ]]; then
_dash_m+="-m"
fi
IFS='|' read -ra SPLIT_MOUNTS <<< "$DIB_MOUNTPOINTS"
for MOUNTPOINT in "${SPLIT_MOUNTS[@]}"; do
if [ "${MOUNTPOINT}" != "/tmp/in_target.d" ] && [ "${MOUNTPOINT}" != "/dev" ] && [ "${MOUNTPOINT}" != "/boot/efi" ]; then
if ! [ -z "${_runcon}" ] && ! pgrep kauditd >/dev/null; then
echo "*** SELinux enabled and kauditd not found, suggesting auditing support is disabled in the host kernel. setfiles will fail without this, please enable and rebuild"
exit 1
fi
if [[ ${MOUNTPOINT} == "/" ]]; then
# If you don't label /dev, /proc and /sys (the actual,
# on-disk directory in the image) correctly, it will have
# bad effects when things like systemd try to do things
# like make network or process namespaces. This generally
# leads to obscure and hard-to-debug failures; [1] has
# plenty of examples.
#
# But right now, /{dev,proc,sys} are mounted! With the
# extant block-device code, we do not have a point to
# break in when these are unmounted, but before we've
# unmounted everything. So we do a hack; for the root
# directory, we bind mount the target so we see the
# underlying directories, and then run setfiles on that.
#
# XXX: we might be able to uncondtionally do this for all
# mountpoints? leaving well enough alone for now...
#
# [1] https://bugzilla.redhat.com/show_bug.cgi?id=1663040
TMP_BIND_MOUNT=$(mktemp -d)
sudo mount --bind ${TARGET_ROOT} ${TMP_BIND_MOUNT}
sudo ${_runcon} chroot ${TMP_BIND_MOUNT} \
/usr/sbin/setfiles -F ${_dash_m} \
/etc/selinux/targeted/contexts/files/file_contexts /
sudo umount ${TMP_BIND_MOUNT}
sudo rmdir ${TMP_BIND_MOUNT}
else
sudo ${_runcon} chroot ${TARGET_ROOT} \
/usr/sbin/setfiles -F ${_dash_m} \
/etc/selinux/targeted/contexts/files/file_contexts ${MOUNTPOINT}
fi
fi
done
|
