Merge branch 'sctp-=security-hook-fixes'

Xin Long says:

====================
security: fixups for the security hooks in sctp

There are a couple of problems in the currect security hooks in sctp:

1. The hooks incorrectly treat sctp_endpoint in SCTP as request_sock in
   TCP, while it's in fact no more than an extension of the sock, and
   represents the local host. It is created when sock is created, not
   when a conn request comes. sctp_association is actually the correct
   one to represent the connection, and created when a conn request
   arrives.

2. security_sctp_assoc_request() hook should also be called in processing
   COOKIE ECHO, as that's the place where the real assoc is created and
   used in the future.

The problems above may cause accept sk, peeloff sk or client sk having
the incorrect security labels.

So this patchset is to change some hooks and pass asoc into them and save
these secids into asoc, as well as add the missing sctp_assoc_request
hook into the COOKIE ECHO processing.

v1->v2:
  - See each patch, and thanks the help from Ondrej, Paul and Richard.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 11 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ea7b2876a5ae..5e5215fe2e83 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5339,10 +5339,10 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
  * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
  * already present).
  */
-static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
+static int selinux_sctp_assoc_request(struct sctp_association *asoc,
 				      struct sk_buff *skb)
 {
-	struct sk_security_struct *sksec = ep->base.sk->sk_security;
+	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 	u8 peerlbl_active;
@@ -5359,7 +5359,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
 		/* This will return peer_sid = SECSID_NULL if there are
 		 * no peer labels, see security_net_peersid_resolve().
 		 */
-		err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
+		err = selinux_skb_peerlbl_sid(skb, asoc->base.sk->sk_family,
 					      &peer_sid);
 		if (err)
 			return err;
@@ -5383,7 +5383,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
 		 */
 		ad.type = LSM_AUDIT_DATA_NET;
 		ad.u.net = &net;
-		ad.u.net->sk = ep->base.sk;
+		ad.u.net->sk = asoc->base.sk;
 		err = avc_has_perm(&selinux_state,
 				   sksec->peer_sid, peer_sid, sksec->sclass,
 				   SCTP_SOCKET__ASSOCIATION, &ad);
@@ -5392,7 +5392,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
 	}
 
 	/* Compute the MLS component for the connection and store
-	 * the information in ep. This will be used by SCTP TCP type
+	 * the information in asoc. This will be used by SCTP TCP type
 	 * sockets and peeled off connections as they cause a new
 	 * socket to be generated. selinux_sctp_sk_clone() will then
 	 * plug this into the new socket.
@@ -5401,11 +5401,11 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
 	if (err)
 		return err;
 
-	ep->secid = conn_sid;
-	ep->peer_secid = peer_sid;
+	asoc->secid = conn_sid;
+	asoc->peer_secid = peer_sid;
 
 	/* Set any NetLabel labels including CIPSO/CALIPSO options. */
-	return selinux_netlbl_sctp_assoc_request(ep, skb);
+	return selinux_netlbl_sctp_assoc_request(asoc, skb);
 }
 
 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
@@ -5490,7 +5490,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
 }
 
 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
-static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
+static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
 				  struct sock *newsk)
 {
 	struct sk_security_struct *sksec = sk->sk_security;
@@ -5502,8 +5502,9 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
 	if (!selinux_policycap_extsockclass())
 		return selinux_sk_clone_security(sk, newsk);
 
-	newsksec->sid = ep->secid;
-	newsksec->peer_sid = ep->peer_secid;
+	if (asoc->secid != SECSID_WILD)
+		newsksec->sid = asoc->secid;
+	newsksec->peer_sid = asoc->peer_secid;
 	newsksec->sclass = sksec->sclass;
 	selinux_netlbl_sctp_sk_clone(sk, newsk);
 }
@@ -5558,6 +5559,16 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
 }
 
+static void selinux_sctp_assoc_established(struct sctp_association *asoc,
+					   struct sk_buff *skb)
+{
+	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+
+	selinux_inet_conn_established(asoc->base.sk, skb);
+	asoc->peer_secid = sksec->peer_sid;
+	asoc->secid = SECSID_WILD;
+}
+
 static int selinux_secmark_relabel_packet(u32 sid)
 {
 	const struct task_security_struct *__tsec;
@@ -7228,6 +7239,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
 	LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
 	LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
+	LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
 	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
 	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
 	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),