[yocto] [meta-selinux][PATCH] selinux-init: use systemd (re)labelling

Thu Sep 5 13:02:11 PDT 2019

[Re: [yocto] [meta-selinux][PATCH] selinux-init: use systemd (re)labelling] On 19.09.05 (Thu 13:55) Mark Asselstine wrote:

> On Friday, August 23, 2019 2:19:53 P.M. EDT Mark Asselstine wrote:
> > Boot loops were being seen when booting with selinux enabled, when the
> > init system in use is systemd. Once logs were retrieved from the
> > failing system the error was found to be
> > 
> > selinux-init.sh[284]: /sbin/restorecon: Could not set context for
> > /sys/fs/cgroup/cpuacct:  Read-only file system selinux-init.sh[284]:
> > /sbin/restorecon: Could not set context for /sys/fs/cgroup/cpu:  Read-only
> > file system
> > 
> > Systemd mounts /sys/fs/cgroup read-only and the (re)labelling code
> > used by selinux-init.sh is unable to handle this. On top of this the
> > system is basically presenting two methods of (re)labelling; using the
> > built in systemd approach via selinux-autorelabel.service *and* the
> > code we have in selinux-init.sh. This can get confusing especially
> > given that most online resources will speak to the systemd approach
> > using selinux-autorelabel.service and /.autorelabel.
> > 
> > These changes leave the current approach in place when sysvinit is the
> > init system used, but if systemd is being used we make use of it's
> > internal (re)labelling functionality. Overall the workflow remains the
> > same but we now avoid boot loops (systemd remounts /sys/fs/cgroup rw
> > during the (re)labelling procedure).
> > 
> > Signed-off-by: Mark Asselstine <mark.asselstine at windriver.com>
> > ---
> 
> Joe, any thoughts on this change?

Not especially, it sounded good to me, seemed to work on a quick test
for my use-case, and I merged it:

http://git.yoctoproject.org/cgit/cgit.cgi/meta-selinux/commit/?id=b0d31db104d9a4e94bc1409c2ffcc1d82f4a780f

Is there something else I should've considered?  Or did you want it on a
different branch too?

-J.

> 
> MarkA
> 
> >  .../selinux/selinux-init/selinux-init.sh           | 14 +-------------
> >  .../selinux/selinux-init/selinux-init.sh.sysvinit  | 14 ++++++++++++++
> >  recipes-security/selinux/selinux-init_0.1.bb       |  8 +++++---
> >  recipes-security/selinux/selinux-initsh.inc        |  8 ++++++++
> >  4 files changed, 28 insertions(+), 16 deletions(-)
> >  create mode 100644
> > recipes-security/selinux/selinux-init/selinux-init.sh.sysvinit
> > 
> > diff --git a/recipes-security/selinux/selinux-init/selinux-init.sh
> > b/recipes-security/selinux/selinux-init/selinux-init.sh index
> > ead4f00..f93d231 100644
> > --- a/recipes-security/selinux/selinux-init/selinux-init.sh
> > +++ b/recipes-security/selinux/selinux-init/selinux-init.sh
> > @@ -33,18 +33,6 @@ check_rootfs()
> >  	/sbin/shutdown -f -h now
> >  }
> > 
> > -# If first booting, the security context type of init would be
> > -# "kernel_t", and the whole file system should be relabeled.
> > -if [ "`${SECON} -t --pid 1`" = "kernel_t" ]; then
> > -	echo "Checking SELinux security contexts:"
> > -	check_rootfs
> > -	echo " * First booting, filesystem will be relabeled..."
> > -	test -x /etc/init.d/auditd && /etc/init.d/auditd start
> > -	${SETENFORCE} 0
> > -	${RESTORECON} -RF /
> > -	${RESTORECON} -F /
> > -	echo " * Relabel done, rebooting the system."
> > -	/sbin/reboot
> > -fi
> > +# sysvinit firstboot relabel placeholder HERE
> > 
> >  exit 0
> > diff --git a/recipes-security/selinux/selinux-init/selinux-init.sh.sysvinit
> > b/recipes-security/selinux/selinux-init/selinux-init.sh.sysvinit new file
> > mode 100644
> > index 0000000..d4f3f71
> > --- /dev/null
> > +++ b/recipes-security/selinux/selinux-init/selinux-init.sh.sysvinit
> > @@ -0,0 +1,14 @@
> > +# Contents will be added to selinux-init.sh to support relabelling with
> > sysvinit +# If first booting, the security context type of init would be
> > +# "kernel_t", and the whole file system should be relabeled.
> > +if [ "`${SECON} -t --pid 1`" = "kernel_t" ]; then
> > +	echo "Checking SELinux security contexts:"
> > +	check_rootfs
> > +	echo " * First booting, filesystem will be relabeled..."
> > +	test -x /etc/init.d/auditd && /etc/init.d/auditd start
> > +	${SETENFORCE} 0
> > +	${RESTORECON} -RF /
> > +	${RESTORECON} -F /
> > +	echo " * Relabel done, rebooting the system."
> > +	/sbin/reboot
> > +fi
> > diff --git a/recipes-security/selinux/selinux-init_0.1.bb
> > b/recipes-security/selinux/selinux-init_0.1.bb index 38b5900..78f571c
> > 100644
> > --- a/recipes-security/selinux/selinux-init_0.1.bb
> > +++ b/recipes-security/selinux/selinux-init_0.1.bb
> > @@ -14,9 +14,11 @@ ${PN}_RDEPENDS = " \
> >      policycoreutils-setfiles \
> >  "
> > 
> > -SRC_URI = "file://${BPN}.sh \
> > -		file://${BPN}.service \
> > -	"
> > +SRC_URI = " \
> > +    file://${BPN}.sh \
> > +    file://${BPN}.sh.sysvinit \
> > +    file://${BPN}.service \
> > +"
> > 
> >  INITSCRIPT_PARAMS = "start 01 S ."
> > 
> > diff --git a/recipes-security/selinux/selinux-initsh.inc
> > b/recipes-security/selinux/selinux-initsh.inc index bcdd449..8e31cda 100644
> > --- a/recipes-security/selinux/selinux-initsh.inc
> > +++ b/recipes-security/selinux/selinux-initsh.inc
> > @@ -17,9 +17,15 @@ inherit update-rc.d systemd
> > 
> >  SYSTEMD_SERVICE_${PN} = "${SELINUX_SCRIPT_SRC}.service"
> > 
> > +FILES_${PN} += "/.autorelabel"
> > +
> >  do_install () {
> >  	install -d ${D}${sysconfdir}/init.d/
> >  	install -m 0755 ${WORKDIR}/${SELINUX_SCRIPT_SRC}.sh
> > ${D}${sysconfdir}/init.d/${SELINUX_SCRIPT_DST} +	# Insert the relabelling
> > code which is only needed with sysvinit +	sed -i -e '/HERE/r
> > ${WORKDIR}/${SELINUX_SCRIPT_SRC}.sh.sysvinit' \ +	       -e '/.*HERE$/d' -e
> > '/.*Contents.*sysvinit/d' \
> > +	       ${D}${sysconfdir}/init.d/${SELINUX_SCRIPT_DST}
> > 
> >  	install -d ${D}${systemd_unitdir}/system
> >  	install -m 0644 ${WORKDIR}/${SELINUX_SCRIPT_SRC}.service
> > ${D}${systemd_unitdir}/system @@ -27,6 +33,8 @@ do_install () {
> >  	if ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'true', 
> 'false',
> > d)}; then install -d ${D}${bindir}
> >  		install -m 0755 ${WORKDIR}/${SELINUX_SCRIPT_SRC}.sh ${D}$
> {bindir}
> > +		sed -i -e '/.*HERE$/d' ${D}${bindir}/$
> {SELINUX_SCRIPT_SRC}.sh
> > +		echo "# first boot relabelling" > ${D}/.autorelabel
> >  	fi
> >  }
> 
> 
> 
> 

-- 
-Joe MacDonald.
Linux Architect | Mentor® A Siemens Business
:wq