entrypoint and execute_no_trans permissions are only ever checked by the
kernel to regular files. They were added to the chr_file class when
execmod was added (which can be checked on chr_file) to ensure that it
was assigned the same value as for the file class, since the kernel code
always checked FILE__EXECMOD. However, the policy definitions are not
necessary since the kernel and policy values have been decoupled ever
since dynamic class/perm support was introduced and further with the
move of execmod to the common definitions, they were not even needed
in the kernel.
These were removed from the kernel's classmap by
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b424485abe2b16580a178b469917a7b6ee0c152a
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Remove unused permission definitions from SELinux.
Many of these were only ever used in pre-mainline
versions of SELinux, prior to Linux 2.6.0. Some of them
were used in the legacy network or compat_net=1 checks
that were disabled by default in Linux 2.6.18 and
fully removed in Linux 2.6.30.
The corresponding classmap declarations were removed from the
mainline kernel in:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=42a9699a9fa179c0054ea3cf5ad3cc67104a6162
Permissions never used in mainline Linux:
file swapon
filesystem transition
tcp_socket { connectto newconn acceptfrom }
node enforce_dest
unix_stream_socket { newconn acceptfrom }
Legacy network checks, removed in 2.6.30:
socket { recv_msg send_msg }
node { tcp_recv tcp_send udp_recv udp_send rawip_recv rawip_send dccp_recv dccp_send }
netif { tcp_recv tcp_send udp_recv udp_send rawip_recv rawip_send dccp_recv dccp_send }
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
When using libvirt to manage virtual machines, libvirt_leaseshelper
wants to:
* read /etc/libnl/classid
* list the content of /sys/devices/system/node/ in order to read files
such as /sys/devices/system/node/node0/meminfo
* use getsched
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
Since systemd 244, systemd can parse EFI variable
SystemdOptions-8cf2644b-4b0b-428f-9387-6d876050dc67 like /proc/cmdline
in order to find options. systemd's NEWS file [1] states:
systemd will also read configuration options from the EFI variable
SystemdOptions. This may be used to configure systemd behaviour when
modifying the kernel command line is inconvenient, but configuration
on disk is read too late, for example for the options related to
cgroup hierarchy setup. 'bootctl systemd-efi-options' may be used to
set the EFI variable.
In practice, all callers of log_parse_environment() read this EFI
variable, because:
* log_parse_environment() is a macro which is expanded to
log_parse_environment_realm(LOG_REALM) [2].
* log_parse_environment_realm() calls proc_cmdline_parse() when being
use in system daemons [3].
* proc_cmdline_parse() always calls systemd_efi_options_variable() [4].
* systemd_efi_options_variable() reads SystemdOptions variable [5].
For SELinux, this means that every domain with attribute
systemd_log_parse_env_type wants to read an EFI variable. Allow this
access.
[1] https://github.com/systemd/systemd/blob/v244/NEWS#L18-L23
[2] https://github.com/systemd/systemd/blob/v244/src/basic/log.h#L84
[3] https://github.com/systemd/systemd/blob/v244/src/basic/log.c#L1116
[4] https://github.com/systemd/systemd/blob/v244/src/basic/proc-cmdline.c#L122
[5] https://github.com/systemd/systemd/blob/v244/src/basic/efivars.c#L242
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
dirmngr needs to listen and accept on /run/user/1000/gnupg/S.dirmngr
type=AVC msg=audit(1554175286.968:2720907): avc: denied { accept } for pid=15692 comm="dirmngr" path="/run/user/1000/gnupg/S.dirmngr" scontext=staff_u:staff_r:dirmngr_t:s0-s0:c0.c1023 tcontext=staff_u:staff_r:dirmngr_t:s0-s0:c0.c1023 tclass=unix_stream_socket permissive=0
Signed-off-by: Jason Zaman <jason@perfinion.com>
CryFS (https://www.cryfs.org/) is a software that can be run by non-root
users that have access to /dev/fuse. Its command is directly used to
mount a directory ("/usr/bin/cryfs basedir mountpoint"), like command
"mount". Unmounting a mountpoint is done with "fusermount -u
mountpoint", /usr/bin/fusermount being a setuid-root program labeled
mount_exec_t.
EncFS (https://www.arg0.net/encfs) is a similar software that has been
considered insecure since a security audit in 2014 found vulnerabilities
that are not yet fixed (like https://github.com/vgough/encfs/issues/9).
gocryptfs (https://nuetzlich.net/gocryptfs/) is a similar software that
has been inspired by EncFS.
Allow users with role sysadm to use all these projects.
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
In order to be able to invoke /usr/bin/mount, /usr/bin/fusermount, etc.
callers need to be able to search /usr/bin. Otherwise, such denials are
recorded:
type=AVC msg=audit(1576534518.220:1320): avc: denied { search }
for pid=24067 comm="cryfs" name="bin" dev="vda1" ino=524829
scontext=sysadm_u:sysadm_r:cryfs_t tcontext=system_u:object_r:bin_t
tclass=dir permissive=0
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
I'm seeing the following error while starting rsyslog:
Nov 17 02:01:38 localhost rsyslogd: cannot create '/run/systemd/journal/syslog': Permission denied [v8.24.0-41.el7_7.2]
Nov 17 02:01:38 localhost rsyslogd: imuxsock does not run because we could not aquire any socket [v8.24.0-41.el7_7.2]
Nov 17 02:01:38 localhost rsyslogd: activation of module imuxsock failed [v8.24.0-41.el7_7.2]
With the following denials:
type=AVC msg=audit(1573958708.773:1896): avc: denied { create } for pid=2347 comm="rsyslogd" name="syslog" scontext=system_u:system_r:syslogd_t:s0 tcontext=system_u:object_r:syslogd_runtime_t:s0 tclass=sock_file permissive=1
type=AVC msg=audit(1573958708.773:1897): avc: denied { setattr } for pid=2347 comm="rsyslogd" name="syslog" dev="tmpfs" ino=19368 scontext=system_u:system_r:syslogd_t:s0 tcontext=system_u:object_r:syslogd_runtime_t:s0 tclass=sock_file permissive=1
Signed-off-by: Dave Sugar <dsugar@tresys.com>
When alsactl is running as a daemon with systemd, it sets its process
priority to be nice to other processes. When stopping the service, it's
signaling to itself that it needs to exit.
----
time->Sun Oct 6 11:59:59 2019
type=AVC msg=audit(1570355999.755:43): avc: denied { setsched } for pid=794 comm="alsactl" scontext=system_u:system_r:alsa_t:s0 tcontext=system_u:system_r:alsa_t:s0 tclass=process permissive=1
----
time->Sun Oct 6 11:59:59 2019
type=AVC msg=audit(1570355999.755:44): avc: denied { getsched } for pid=794 comm="alsactl" scontext=system_u:system_r:alsa_t:s0 tcontext=system_u:system_r:alsa_t:s0 tclass=process permissive=1
----
time->Sun Oct 6 12:07:26 2019
type=AVC msg=audit(1570356446.747:292): avc: denied { signal } for pid=3585 comm="alsactl" scontext=system_u:system_r:alsa_t:s0 tcontext=system_u:system_r:alsa_t:s0 tclass=process permissive=1
Signed-off-by: Laurent Bigonville <bigon@bigon.be>
