kernel_optimize_test/security/selinux
Ondrej Mosnacek fede148324 selinux: log invalid contexts in AVCs
In case a file has an invalid context set, in an AVC record generated
upon access to such file, the target context is always reported as
unlabeled. This patch adds new optional fields to the AVC record
(srawcon and trawcon) that report the actual context string if it
differs from the one reported in scontext/tcontext. This is useful for
diagnosing SELinux denials involving invalid contexts.

To trigger an AVC that illustrates this situation:

    # setenforce 0
    # touch /tmp/testfile
    # setfattr -n security.selinux -v system_u:object_r:banana_t:s0 /tmp/testfile
    # runcon system_u:system_r:sshd_t:s0 cat /tmp/testfile

AVC before:

type=AVC msg=audit(1547801083.248:11): avc:  denied  { open } for  pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1

AVC after:

type=AVC msg=audit(1547801083.248:11): avc:  denied  { open } for  pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1 trawcon=system_u:object_r:banana_t:s0

Note that it is also possible to encounter this situation with the
'scontext' field - e.g. when a new policy is loaded while a process is
running, whose context is not valid in the new policy.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1135683

Cc: Daniel Walsh <dwalsh@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-25 17:31:14 -05:00
..
include selinux: log invalid contexts in AVCs 2019-01-25 17:31:14 -05:00
ss selinux: log invalid contexts in AVCs 2019-01-25 17:31:14 -05:00
.gitignore
avc.c selinux: log invalid contexts in AVCs 2019-01-25 17:31:14 -05:00
exports.c
hooks.c selinux: do not override context on context mounts 2019-01-10 21:24:43 -05:00
ibpkey.c selinux: wrap global selinux state 2018-03-01 18:48:02 -05:00
Kconfig
Makefile
netif.c selinux: Cleanup printk logging in netif 2018-06-19 13:45:31 -04:00
netlabel.c selinux: wrap AVC state 2018-03-20 16:58:17 -04:00
netlink.c selinux: Cleanup printk logging in netlink 2018-06-19 13:33:05 -04:00
netnode.c selinux: Cleanup printk logging in netnode 2018-06-19 13:49:10 -04:00
netport.c selinux: Cleanup printk logging in netport 2018-06-19 13:43:01 -04:00
nlmsgtab.c selinux: add support for RTM_NEWCHAIN, RTM_DELCHAIN, and RTM_GETCHAIN 2018-11-29 11:32:02 -05:00
selinuxfs.c selinux/stable-4.18 PR 20180814 2018-08-15 10:39:06 -07:00
xfrm.c net: use skb_sec_path helper in more places 2018-12-19 11:21:37 -08:00