security: pass asoc to sctp_assoc_request and sctp_sk_clone

This patch is to move secid and peer_secid from endpoint to association,
and pass asoc to sctp_assoc_request and sctp_sk_clone instead of ep. As
ep is the local endpoint and asoc represents a connection, and in SCTP
one sk/ep could have multiple asoc/connection, saving secid/peer_secid
for new asoc will overwrite the old asoc's.

Note that since asoc can be passed as NULL, security_sctp_assoc_request()
is moved to the place right after the new_asoc is created in
sctp_sf_do_5_1B_init() and sctp_sf_do_unexpected_init().

v1->v2:
  - fix the description of selinux_netlbl_skbuff_setsid(), as Jakub noticed.
  - fix the annotation in selinux_sctp_assoc_request(), as Richard Noticed.

Fixes: 72e89f50084c ("security: Add support for SCTP security hooks")
Reported-by: Prashanth Prahlad <pprahlad@redhat.com>
Reviewed-by: Richard Haines <richard_c_haines@btinternet.com>
Tested-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 16 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index fb3da4d8f4a3..3206374209bc 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -326,11 +326,6 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
 	struct sctp_packet *packet;
 	int len;
 
-	/* Update socket peer label if first association. */
-	if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
-					chunk->skb))
-		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
-
 	/* 6.10 Bundling
 	 * An endpoint MUST NOT bundle INIT, INIT ACK or
 	 * SHUTDOWN COMPLETE with any other chunks.
@@ -415,6 +410,12 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
 	if (!new_asoc)
 		goto nomem;
 
+	/* Update socket peer label if first association. */
+	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
+		sctp_association_free(new_asoc);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+	}
+
 	if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
 					     sctp_scope(sctp_source(chunk)),
 					     GFP_ATOMIC) < 0)
@@ -780,7 +781,6 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
 		}
 	}
 
-
 	/* Delay state machine commands until later.
 	 *
 	 * Re-build the bind address for the association is done in
@@ -1517,11 +1517,6 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
 	struct sctp_packet *packet;
 	int len;
 
-	/* Update socket peer label if first association. */
-	if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
-					chunk->skb))
-		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
-
 	/* 6.10 Bundling
 	 * An endpoint MUST NOT bundle INIT, INIT ACK or
 	 * SHUTDOWN COMPLETE with any other chunks.
@@ -1594,6 +1589,12 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
 	if (!new_asoc)
 		goto nomem;
 
+	/* Update socket peer label if first association. */
+	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
+		sctp_association_free(new_asoc);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+	}
+
 	if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
 				sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
 		goto nomem;
@@ -2255,8 +2256,7 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
 	}
 
 	/* Update socket peer label if first association. */
-	if (security_sctp_assoc_request((struct sctp_endpoint *)ep,
-					chunk->skb)) {
+	if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
 		sctp_association_free(new_asoc);
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 	}
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 6b937bfd4751..33391254fa82 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9412,7 +9412,6 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 	struct inet_sock *inet = inet_sk(sk);
 	struct inet_sock *newinet;
 	struct sctp_sock *sp = sctp_sk(sk);
-	struct sctp_endpoint *ep = sp->ep;
 
 	newsk->sk_type = sk->sk_type;
 	newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
@@ -9457,9 +9456,9 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 		net_enable_timestamp();
 
 	/* Set newsk security attributes from original sk and connection
-	 * security attribute from ep.
+	 * security attribute from asoc.
 	 */
-	security_sctp_sk_clone(ep, sk, newsk);
+	security_sctp_sk_clone(asoc, sk, newsk);
 }
 
 static inline void sctp_copy_descendant(struct sock *sk_to,