I'm seeing problems on RHEL7 with lvm2-activation-generator that are
coming from recent changes to put systemd-fstab-generator into it's
own domain. I resolved the issues by creaing this generator attribute
to grant common generator permissions and move all generators into
a single systemd_generator_t domain.
Then setup specific types for the following generators:
lvm2-activation-generator - needs to read lvm2 config
systemd-sysv-generator - needs to read stuff in init_t that other generators don't.
systemd-efi-boot-generator - needs to read stuff on the EFI boot partition labeled boot_t
For fstab generator allow it to write /sys
[ 19.482951] type=1400 audit(1584548691.268:7): avc: denied { write } for pid=1638 comm="systemd-fstab-g" name="/" dev="sysfs" ino=1 Allow scontext=system_u:system_r:systemd_fstab_generator_t:s0 tcontext=system_u:object_r:sysfs_t:s0 tclass=dir permissive=1
audit(1585500099.139:6): avc: denied { read } for pid=1635 comm="systemd-cryptse" path="/run/systemd/generator/dev-mapper-luks\x2d6a613af0\x2d0a61\x2d462f\x2d8679\x2d1b0d964fbc88.device.d/.#90-device-timeout.confsOskdU" dev="tmpfs" ino=12243 scontext=system_u:system_r:systemd_generator_t:s0 tcontext=system_u:object_r:init_runtime_t:s0 tclass=file permissive=1
audit(1585500099.139:7): avc: denied { setattr } for pid=1635 comm="systemd-cryptse" name=".#90-device-timeout.confsOskdU" dev="tmpfs" ino=12243 scontext=system_u:system_r:systemd_generator_t:s0 tcontext=system_u:object_r:init_runtime_t:s0 tclass=file permissive=1
audit(1585500099.139:8): avc: denied { rename } for pid=1635 comm="systemd-cryptse" name=".#90-device-timeout.confsOskdU" dev="tmpfs" ino=12243 scontext=system_u:system_r:systemd_generator_t:s0 tcontext=system_u:object_r:init_runtime_t:s0 tclass=file permissive=1
Signed-off-by: Dave Sugar <dsugar@tresys.com>
auditd can halt the system for several reasons based on configuration.
These mostly revovle around audit partition full issues. I am seeing
the following denials when attempting to halt the system.
Jan 12 03:38:48 localhost audispd: node=localhost type=USER_AVC msg=audit(1578800328.122:1943): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='avc: denied { start } for auid=n/a uid=0 gid=0 path="/usr/lib/systemd/system/poweroff.target" cmdline="/sbin/init 0" scontext=system_u:system_r:auditd_t:s0 tcontext=system_u:object_r:power_unit_t:s0 tclass=service exe="/usr/lib/systemd/systemd" sauid=0 hostname=? addr=? terminal=?'
Jan 12 03:38:48 localhost audispd: node=localhost type=USER_AVC msg=audit(1578800328.147:1944): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='avc: denied { status } for auid=n/a uid=0 gid=0 path="/usr/lib/systemd/system/poweroff.target" cmdline="/sbin/init 0" scontext=system_u:system_r:auditd_t:s0 tcontext=system_u:object_r:power_unit_t:s0 tclass=service exe="/usr/lib/systemd/systemd" sauid=0 hostname=? addr=? terminal=?'
Jan 12 04:44:54 localhost audispd: node=localhost type=AVC msg=audit(1578804294.103:1923): avc: denied { getattr } for pid=6936 comm="systemctl" path="/run/systemd/system" dev="tmpfs" ino=45 scontext=system_u:system_r:auditd_t:s0 tcontext=system_u:object_r:systemd_unit_t:s0 tclass=dir permissive=1
v2 - use optional rather than ifdef
v3 - fix order
Signed-off-by: Dave Sugar <dsugar@tresys.com>
systemd's Name Service Switch (NSS) module provides UNIX user and group
name resolution for dynamic users and groups allocated through options
such as DynamicUser= in systemd unit files, according to its man page,
https://github.com/systemd/systemd/blob/v244/man/nss-systemd.xml.
If systemd compiled without NOLEGACY, commit
24eccc3414
("nss-systemd,user-util: add a way how synthesizing "nobody" can be
turned off") implemented a way to tweak nss-systemd's behavior by
checking whether /etc/systemd/dont-synthesize-nobody exists. Allow this
access.
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
"systemd --user" spawns programs from
/usr/lib/systemd/user-environment-generators/ in order to gather
environment variables. On a Debian 10 virtual machine which gnupg, this
directory contains:
$ ls -Z /usr/lib/systemd/user-environment-generators
system_u:object_r:bin_t 30-systemd-environment-d-generator
system_u:object_r:bin_t 90gpg-agent
For sysadm, these programs are run as sysadm_t (because there is a
transition in systemd_role_template() in systemd.if:
corecmd_bin_domtrans($1_systemd_t, $3)) but use file descriptors created
by their parent process, which runs as sysadm_systemd_t. This leads to:
type=AVC msg=audit(1569756917.537:244): avc: denied { use } for
pid=9713 comm="30-systemd-envi"
path=2F6D656D66643A33302D73797374656D642D656E7669726F6E6D656E742D642D67656E657261746F72202864656C6574656429
dev="tmpfs" ino=24859 scontext=sysadm_u:sysadm_r:sysadm_t
tcontext=sysadm_u:sysadm_r:sysadm_systemd_t tclass=fd permissive=0
type=AVC msg=audit(1569756917.537:244): avc: denied { use } for
pid=9713 comm="30-systemd-envi"
path="/usr/lib/systemd/user-environment-generators/30-systemd-environment-d-generator"
dev="vda1" ino=655822 scontext=sysadm_u:sysadm_r:sysadm_t
tcontext=sysadm_u:sysadm_r:sysadm_systemd_t tclass=fd permissive=0
type=SYSCALL msg=audit(1569756917.537:244): arch=c000003e syscall=59
success=no exit=-13 a0=5647d12cf020 a1=7ffc605b1fb0 a2=7ffc605b2420
a3=0 items=0 ppid=9712 pid=9713 auid=1000 uid=1000 gid=1000
euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000
tty=(none) ses=10 comm="30-systemd-envi"
exe="/usr/lib/systemd/user-environment-generators/30-systemd-environment-d-generator"
subj=sysadm_u:sysadm_r:sysadm_t key=(null)
[...]
type=AVC msg=audit(1569756917.541:246): avc: denied { use } for
pid=9714 comm="90gpg-agent"
path=2F6D656D66643A39306770672D6167656E74202864656C6574656429
dev="tmpfs" ino=24860 scontext=sysadm_u:sysadm_r:sysadm_t
tcontext=sysadm_u:sysadm_r:sysadm_systemd_t tclass=fd permissive=0
type=AVC msg=audit(1569756917.541:246): avc: denied { use } for
pid=9714 comm="90gpg-agent" path="/usr/bin/bash" dev="vda1"
ino=524662 scontext=sysadm_u:sysadm_r:sysadm_t
tcontext=sysadm_u:sysadm_r:sysadm_systemd_t tclass=fd permissive=0
In systemd's source, here are the relevant functions:
* manager_run_environment_generators() calls execute_directories(paths,
DEFAULT_TIMEOUT_USEC, gather_environment, ...) [1], with
gather_environment a global table defined in exec-util.c [2]
* execute_directories() opens a "serialization fd" [3], that creates a
memfd for communication with the child processes [4].
* execute_directories() calls fork() and do_execute() [5] in order to
run each child process, providing them with the memfd descriptor in
order to gather their output.
* When a child process is executed, its context transitions from
sysadm_systemd_t to sysadm_t. The child then writes environment
variables to its output.
* The parent process (systemd --user) collects the environment variables
that have been written, and "consumes" the produced output in order to
override its environment variables.
[1] https://github.com/systemd/systemd/blob/v243/src/core/manager.c#L3836
[2] https://github.com/systemd/systemd/blob/v243/src/shared/exec-util.c#L413
[3] https://github.com/systemd/systemd/blob/v243/src/shared/exec-util.c#L213
[4] https://github.com/systemd/systemd/blob/v243/src/shared/serialize.c#L200
[5] https://github.com/systemd/systemd/blob/v243/src/shared/exec-util.c#L226
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
When a service is configured with PrivateDevices=yes, its /dev directory
has label tmpfs_t. This requires allowing more accesses in order for the
service to use /dev.
This is related to https://github.com/SELinuxProject/refpolicy/pull/61
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
I'm seeing a denial for udev to map /etc/udev/hwdb.bin.
This creates and uses a new interface to allow the needed
permission for udev.
type=AVC msg=audit(1551886176.948:642): avc: denied { map } for pid=5187 comm="systemd-udevd" path="/etc/udev/hwdb.bin" dev="dm-1" ino=6509618 scontext=system_u:system_r:udev_t:s0-s0:c0.c1023 tcontext=system_u:object_r:systemd_hwdb_t:s0 tclass=file permissive=1
Updated from previous to create a new interface.
Signed-off-by: Dave Sugar <dsugar@tresys.com>
systemd-hwdb rebuilds /etc/udev/hwdb.bin from files in /var/lib/udev/hwdb.d/*
making a temp file first in /etc/udev/ then moving the tmp file
over hwdb.bin when complete. It also relabels based in file_contexts
This provides private type for /etc/udev/hwdb.bin
Signed-off-by: Dave Sugar <dsugar@tresys.com>
systemd-update-done needs to be able to create /etc/.updated and /var/.updated
Jun 6 13:11:58 localhost systemd-update-done: Failed to create timestamp file /etc/.updated: Permission denied
Jun 6 13:11:58 localhost systemd-update-done: Failed to create timestamp file /var/.updated: Permission denied
Jun 6 13:11:58 localhost systemd: systemd-update-done.service: main process exited, code=exited, status=1/FAILURE
Jun 6 13:11:58 localhost systemd: Failed to start Update is Completed.
Jun 6 13:11:58 localhost systemd: Unit systemd-update-done.service entered failed state.
Jun 6 13:11:58 localhost systemd: systemd-update-done.service failed.
Signed-off-by: Dave Sugar <dsugar@tresys.com>
Policy needed for systemd-networkd to function. This is based on a patch from krzysztof.a.nowicki at gmail.com that was submitted back in May (I talked to him via email a while ago about me picking up the patch). He was too busy to update and I needed to get it working.
I am pretty sure I updated everything mentioned in previous feedback, please comment if something is still off and I will revise.
Signed-off-by: Dave Sugar <dsugar@tresys.com>
systemd relabels everything in /dev and /run after loading the policy.
In these directories there is a socket file for udev, /run/udev/control,
which is not allowed to be relabelled from tmpfs_t:
avc: denied { relabelfrom } for pid=1 comm="systemd"
name="control" dev="tmpfs" ino=7027
scontext=system_u:system_r:init_t tcontext=system_u:object_r:tmpfs_t
tclass=sock_file permissive=1
avc: denied { relabelto } for pid=1 comm="systemd" name="control"
dev="tmpfs" ino=7027 scontext=system_u:system_r:init_t
tcontext=system_u:object_r:udev_var_run_t tclass=sock_file
permissive=1
/run/tmpfiles.d directory (used by systemd-tmpfiles service) is also
relabelled.
This patch adds an interface to manage systemd_passwd_var_run_t symlinks that
I'll add another patch to use shortly.
It has a number of changes needed by systemd_logind_t to set permissions for
local logins.
It has some more permissions that systemd_machined_t needs, I don't think it's
everything that systemd_machined_t needs but it's a start.
It has some changes for udev_t for systemd-udevd.
bauen1
Dave Sugar
Chris PeBenito
Nicolas Iooss
Chris PeBenito
Daniel Burgener
Chris PeBenito
Russell Coker
Laurent Bigonville
cgzones
Dominick Grift
Chris PeBenito