SELinux: Return correct context for SO_PEERSEC

Fix SO_PEERSEC for tcp sockets to return the security context of
the peer (as represented by the SA from the peer) as opposed to the
SA used by the local/source socket.

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

1 files changed, 3 insertions, 37 deletions

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 4d5a043..8fef742 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -184,7 +184,8 @@ int selinux_xfrm_flow_state_match(struct flowi *fl, struct xfrm_state *xfrm,
 }
 
 /*
- * LSM hook implementation that determines the sid for the session.
+ * LSM hook implementation that checks and/or returns the xfrm sid for the
+ * incoming packet.
  */
 
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
@@ -403,43 +404,8 @@ void selinux_xfrm_state_free(struct xfrm_state *x)
 }
 
 /*
- * SELinux internal function to retrieve the context of a connected
- * (sk->sk_state == TCP_ESTABLISHED) TCP socket based on its security
- * association used to connect to the remote socket.
- *
- * Retrieve via getsockopt SO_PEERSEC.
- */
-u32 selinux_socket_getpeer_stream(struct sock *sk)
-{
-	struct dst_entry *dst, *dst_test;
-	u32 peer_sid = SECSID_NULL;
-
-	if (sk->sk_state != TCP_ESTABLISHED)
-		goto out;
-
-	dst = sk_dst_get(sk);
-	if (!dst)
-		goto out;
-
- 	for (dst_test = dst; dst_test != 0;
-      	     dst_test = dst_test->child) {
-		struct xfrm_state *x = dst_test->xfrm;
-
- 		if (x && selinux_authorizable_xfrm(x)) {
-	 	 	struct xfrm_sec_ctx *ctx = x->security;
-			peer_sid = ctx->ctx_sid;
-			break;
-		}
-	}
-	dst_release(dst);
-
-out:
-	return peer_sid;
-}
-
-/*
  * SELinux internal function to retrieve the context of a UDP packet
- * based on its security association used to connect to the remote socket.
+ * based on its security association.
  *
  * Retrieve via setsockopt IP_PASSSEC and recvmsg with control message
  * type SCM_SECURITY.