SELinux: Fix SA selection semantics

Fix the selection of an SA for an outgoing packet to be at the same
context as the originating socket/flow. This eliminates the SELinux
policy's ability to use/sendto SAs with contexts other than the socket's.

With this patch applied, the SELinux policy will require one or more of the
following for a socket to be able to communicate with/without SAs:

1. To enable a socket to communicate without using labeled-IPSec SAs:

allow socket_t unlabeled_t:association { sendto recvfrom }

2. To enable a socket to communicate with labeled-IPSec SAs:

allow socket_t self:association { sendto };
allow socket_t peer_sa_t:association { recvfrom };

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 7736b23c3f03..b88b038530c9 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1894,7 +1894,8 @@ int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
 
                 if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
                         return 0;
-                if (fl && !security_xfrm_flow_state_match(fl, dst->xfrm, pol))
+                if (fl && pol &&
+                    !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
                         return 0;
                 if (dst->xfrm->km.state != XFRM_STATE_VALID)
                         return 0;