linux/security/selinux
Stephen Smalley 59438b4647 security,lockdown,selinux: implement SELinux lockdown
Implement a SELinux hook for lockdown.  If the lockdown module is also
enabled, then a denial by the lockdown module will take precedence over
SELinux, so SELinux can only further restrict lockdown decisions.
The SELinux hook only distinguishes at the granularity of integrity
versus confidentiality similar to the lockdown module, but includes the
full lockdown reason as part of the audit record as a hint in diagnosing
what triggered the denial.  To support this auditing, move the
lockdown_reasons[] string array from being private to the lockdown
module to the security framework so that it can be used by the lsm audit
code and so that it is always available even when the lockdown module
is disabled.

Note that the SELinux implementation allows the integrity and
confidentiality reasons to be controlled independently from one another.
Thus, in an SELinux policy, one could allow operations that specify
an integrity reason while blocking operations that specify a
confidentiality reason. The SELinux hook implementation is
stricter than the lockdown module in validating the provided reason value.

Sample AVC audit output from denials:
avc:  denied  { integrity } for pid=3402 comm="fwupd"
 lockdown_reason="/dev/mem,kmem,port" scontext=system_u:system_r:fwupd_t:s0
 tcontext=system_u:system_r:fwupd_t:s0 tclass=lockdown permissive=0

avc:  denied  { confidentiality } for pid=4628 comm="cp"
 lockdown_reason="/proc/kcore access"
 scontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
 tcontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
 tclass=lockdown permissive=0

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
[PM: some merge fuzz do the the perf hooks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09 17:53:58 -05:00
..
include security,lockdown,selinux: implement SELinux lockdown 2019-12-09 17:53:58 -05:00
ss selinux: cache the SID -> context string translation 2019-12-09 16:14:51 -05:00
.gitignore SELinux: add .gitignore files for dynamic classes 2009-10-24 09:42:27 +08:00
avc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
hooks.c security,lockdown,selinux: implement SELinux lockdown 2019-12-09 17:53:58 -05:00
ibpkey.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
Kconfig selinux: cache the SID -> context string translation 2019-12-09 16:14:51 -05:00
Makefile SELinux: Remove unused selinux_is_enabled 2019-01-08 13:18:44 -08:00
netif.c selinux/stable-5.4 PR 20190917 2019-09-23 11:21:04 -07:00
netlabel.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
netnode.c selinux/stable-5.4 PR 20190917 2019-09-23 11:21:04 -07:00
netport.c selinux/stable-5.4 PR 20190917 2019-09-23 11:21:04 -07:00
nlmsgtab.c net: rtnetlink: add linkprop commands to add and delete alternative ifnames 2019-10-01 14:47:19 -07:00
selinuxfs.c selinux: sidtab reverse lookup hash table 2019-12-09 16:14:51 -05:00
xfrm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00