selinux: Add SCTP support

The SELinux SCTP implementation is explained in:
Documentation/security/SELinux-sctp.rst

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

6 files changed, 565 insertions, 32 deletions

diff --git a/Documentation/security/SELinux-sctp.rst b/Documentation/security/SELinux-sctp.rst
new file mode 100644
index 000000000000..2f66bf30658a
--- /dev/null
+++ b/Documentation/security/SELinux-sctp.rst
@@ -0,0 +1,157 @@
+SCTP SELinux Support
+=====================
+
+Security Hooks
+===============
+
+``Documentation/security/LSM-sctp.rst`` describes the following SCTP security
+hooks with the SELinux specifics expanded below::
+
+    security_sctp_assoc_request()
+    security_sctp_bind_connect()
+    security_sctp_sk_clone()
+    security_inet_conn_established()
+
+
+security_sctp_assoc_request()
+-----------------------------
+Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the
+security module. Returns 0 on success, error on failure.
+::
+
+    @ep - pointer to sctp endpoint structure.
+    @skb - pointer to skbuff of association packet.
+
+The security module performs the following operations:
+     IF this is the first association on ``@ep->base.sk``, then set the peer
+     sid to that in ``@skb``. This will ensure there is only one peer sid
+     assigned to ``@ep->base.sk`` that may support multiple associations.
+
+     ELSE validate the ``@ep->base.sk peer_sid`` against the ``@skb peer sid``
+     to determine whether the association should be allowed or denied.
+
+     Set the sctp ``@ep sid`` to socket's sid (from ``ep->base.sk``) with
+     MLS portion taken from ``@skb peer sid``. This will be used by SCTP
+     TCP style sockets and peeled off connections as they cause a new socket
+     to be generated.
+
+     If IP security options are configured (CIPSO/CALIPSO), then the ip
+     options are set on the socket.
+
+
+security_sctp_bind_connect()
+-----------------------------
+Checks permissions required for ipv4/ipv6 addresses based on the ``@optname``
+as follows::
+
+  ------------------------------------------------------------------
+  |                   BIND Permission Checks                       |
+  |       @optname             |         @address contains         |
+  |----------------------------|-----------------------------------|
+  | SCTP_SOCKOPT_BINDX_ADD     | One or more ipv4 / ipv6 addresses |
+  | SCTP_PRIMARY_ADDR          | Single ipv4 or ipv6 address       |
+  | SCTP_SET_PEER_PRIMARY_ADDR | Single ipv4 or ipv6 address       |
+  ------------------------------------------------------------------
+
+  ------------------------------------------------------------------
+  |                 CONNECT Permission Checks                      |
+  |       @optname             |         @address contains         |
+  |----------------------------|-----------------------------------|
+  | SCTP_SOCKOPT_CONNECTX      | One or more ipv4 / ipv6 addresses |
+  | SCTP_PARAM_ADD_IP          | One or more ipv4 / ipv6 addresses |
+  | SCTP_SENDMSG_CONNECT       | Single ipv4 or ipv6 address       |
+  | SCTP_PARAM_SET_PRIMARY     | Single ipv4 or ipv6 address       |
+  ------------------------------------------------------------------
+
+
+``Documentation/security/LSM-sctp.rst`` gives a summary of the ``@optname``
+entries and also describes ASCONF chunk processing when Dynamic Address
+Reconfiguration is enabled.
+
+
+security_sctp_sk_clone()
+-------------------------
+Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style
+socket) or when a socket is 'peeled off' e.g userspace calls
+**sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new
+sockets sid and peer sid to that contained in the ``@ep sid`` and
+``@ep peer sid`` respectively.
+::
+
+    @ep - pointer to current sctp endpoint structure.
+    @sk - pointer to current sock structure.
+    @sk - pointer to new sock structure.
+
+
+security_inet_conn_established()
+---------------------------------
+Called when a COOKIE ACK is received where it sets the connection's peer sid
+to that in ``@skb``::
+
+    @sk  - pointer to sock structure.
+    @skb - pointer to skbuff of the COOKIE ACK packet.
+
+
+Policy Statements
+==================
+The following class and permissions to support SCTP are available within the
+kernel::
+
+    class sctp_socket inherits socket { node_bind }
+
+whenever the following policy capability is enabled::
+
+    policycap extended_socket_class;
+
+SELinux SCTP support adds the ``name_connect`` permission for connecting
+to a specific port type and the ``association`` permission that is explained
+in the section below.
+
+If userspace tools have been updated, SCTP will support the ``portcon``
+statement as shown in the following example::
+
+    portcon sctp 1024-1036 system_u:object_r:sctp_ports_t:s0
+
+
+SCTP Peer Labeling
+===================
+An SCTP socket will only have one peer label assigned to it. This will be
+assigned during the establishment of the first association. Once the peer
+label has been assigned, any new associations will have the ``association``
+permission validated by checking the socket peer sid against the received
+packets peer sid to determine whether the association should be allowed or
+denied.
+
+NOTES:
+   1) If peer labeling is not enabled, then the peer context will always be
+      ``SECINITSID_UNLABELED`` (``unlabeled_t`` in Reference Policy).
+
+   2) As SCTP can support more than one transport address per endpoint
+      (multi-homing) on a single socket, it is possible to configure policy
+      and NetLabel to provide different peer labels for each of these. As the
+      socket peer label is determined by the first associations transport
+      address, it is recommended that all peer labels are consistent.
+
+   3) **getpeercon**\(3) may be used by userspace to retrieve the sockets peer
+      context.
+
+   4) While not SCTP specific, be aware when using NetLabel that if a label
+      is assigned to a specific interface, and that interface 'goes down',
+      then the NetLabel service will remove the entry. Therefore ensure that
+      the network startup scripts call **netlabelctl**\(8) to set the required
+      label (see **netlabel-config**\(8) helper script for details).
+
+   5) The NetLabel SCTP peer labeling rules apply as discussed in the following
+      set of posts tagged "netlabel" at: http://www.paul-moore.com/blog/t.
+
+   6) CIPSO is only supported for IPv4 addressing: ``socket(AF_INET, ...)``
+      CALIPSO is only supported for IPv6 addressing: ``socket(AF_INET6, ...)``
+
+      Note the following when testing CIPSO/CALIPSO:
+         a) CIPSO will send an ICMP packet if an SCTP packet cannot be
+            delivered because of an invalid label.
+         b) CALIPSO does not send an ICMP packet, just silently discards it.
+
+   7) IPSEC is not supported as RFC 3554 - sctp/ipsec support has not been
+      implemented in userspace (**racoon**\(8) or **ipsec_pluto**\(8)),
+      although the kernel supports SCTP/IPSEC.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8644d864e3c1..28a5c4ee0705 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -67,6 +67,8 @@
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/dccp.h>
+#include <linux/sctp.h>
+#include <net/sctp/structs.h>
 #include <linux/quota.h>
 #include <linux/un.h>           /* for Unix socket types */
 #include <net/af_unix.h>        /* for Unix socket types */
@@ -4134,6 +4136,23 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
                 break;
         }
 
+#if IS_ENABLED(CONFIG_IP_SCTP)
+        case IPPROTO_SCTP: {
+                struct sctphdr _sctph, *sh;
+
+                if (ntohs(ih->frag_off) & IP_OFFSET)
+                        break;
+
+                offset += ihlen;
+                sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
+                if (sh == NULL)
+                        break;
+
+                ad->u.net->sport = sh->source;
+                ad->u.net->dport = sh->dest;
+                break;
+        }
+#endif
         default:
                 break;
         }
@@ -4207,6 +4226,19 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
                 break;
         }
 
+#if IS_ENABLED(CONFIG_IP_SCTP)
+        case IPPROTO_SCTP: {
+                struct sctphdr _sctph, *sh;
+
+                sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
+                if (sh == NULL)
+                        break;
+
+                ad->u.net->sport = sh->source;
+                ad->u.net->dport = sh->dest;
+                break;
+        }
+#endif
         /* includes fragments */
         default:
                 break;
@@ -4396,6 +4428,10 @@ static int selinux_socket_post_create(struct socket *sock, int family,
                 sksec = sock->sk->sk_security;
                 sksec->sclass = sclass;
                 sksec->sid = sid;
+                /* Allows detection of the first association on this socket */
+                if (sksec->sclass == SECCLASS_SCTP_SOCKET)
+                        sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
+
                 err = selinux_netlbl_socket_post_create(sock->sk, family);
         }
 
@@ -4416,11 +4452,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
         if (err)
                 goto out;
 
-        /*
-         * If PF_INET or PF_INET6, check name_bind permission for the port.
-         * Multiple address binding for SCTP is not supported yet: we just
-         * check the first address now.
-         */
+        /* If PF_INET or PF_INET6, check name_bind permission for the port. */
         family = sk->sk_family;
         if (family == PF_INET || family == PF_INET6) {
                 char *addrp;
@@ -4432,7 +4464,13 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
                 unsigned short snum;
                 u32 sid, node_perm;
 
-                if (family == PF_INET) {
+                /*
+                 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
+                 * that validates multiple binding addresses. Because of this
+                 * need to check address->sa_family as it is possible to have
+                 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
+                 */
+                if (address->sa_family == AF_INET) {
                         if (addrlen < sizeof(struct sockaddr_in)) {
                                 err = -EINVAL;
                                 goto out;
@@ -4486,6 +4524,10 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
                         node_perm = DCCP_SOCKET__NODE_BIND;
                         break;
 
+                case SECCLASS_SCTP_SOCKET:
+                        node_perm = SCTP_SOCKET__NODE_BIND;
+                        break;
+
                 default:
                         node_perm = RAWIP_SOCKET__NODE_BIND;
                         break;
@@ -4500,7 +4542,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
                 ad.u.net->sport = htons(snum);
                 ad.u.net->family = family;
 
-                if (family == PF_INET)
+                if (address->sa_family == AF_INET)
                         ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
                 else
                         ad.u.net->v6info.saddr = addr6->sin6_addr;
@@ -4514,7 +4556,11 @@ out:
         return err;
 }
 
-static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
+/* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
+ * and sctp_sendmsg(3) as described in Documentation/security/LSM-sctp.txt
+ */
+static int selinux_socket_connect_helper(struct socket *sock,
+                                         struct sockaddr *address, int addrlen)
 {
         struct sock *sk = sock->sk;
         struct sk_security_struct *sksec = sk->sk_security;
@@ -4525,10 +4571,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
                 return err;
 
         /*
-         * If a TCP or DCCP socket, check name_connect permission for the port.
+         * If a TCP, DCCP or SCTP socket, check name_connect permission
+         * for the port.
          */
         if (sksec->sclass == SECCLASS_TCP_SOCKET ||
-            sksec->sclass == SECCLASS_DCCP_SOCKET) {
+            sksec->sclass == SECCLASS_DCCP_SOCKET ||
+            sksec->sclass == SECCLASS_SCTP_SOCKET) {
                 struct common_audit_data ad;
                 struct lsm_network_audit net = {0,};
                 struct sockaddr_in *addr4 = NULL;
@@ -4536,7 +4584,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
                 unsigned short snum;
                 u32 sid, perm;
 
-                if (sk->sk_family == PF_INET) {
+                /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
+                 * that validates multiple connect addresses. Because of this
+                 * need to check address->sa_family as it is possible to have
+                 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
+                 */
+                if (address->sa_family == AF_INET) {
                         addr4 = (struct sockaddr_in *)address;
                         if (addrlen < sizeof(struct sockaddr_in))
                                 return -EINVAL;
@@ -4550,10 +4603,19 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
 
                 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
                 if (err)
-                        goto out;
+                        return err;
 
-                perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
-                       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
+                switch (sksec->sclass) {
+                case SECCLASS_TCP_SOCKET:
+                        perm = TCP_SOCKET__NAME_CONNECT;
+                        break;
+                case SECCLASS_DCCP_SOCKET:
+                        perm = DCCP_SOCKET__NAME_CONNECT;
+                        break;
+                case SECCLASS_SCTP_SOCKET:
+                        perm = SCTP_SOCKET__NAME_CONNECT;
+                        break;
+                }
 
                 ad.type = LSM_AUDIT_DATA_NET;
                 ad.u.net = &net;
@@ -4561,13 +4623,24 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
                 ad.u.net->family = sk->sk_family;
                 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
                 if (err)
-                        goto out;
+                        return err;
         }
 
-        err = selinux_netlbl_socket_connect(sk, address);
+        return 0;
+}
 
-out:
-        return err;
+/* Supports connect(2), see comments in selinux_socket_connect_helper() */
+static int selinux_socket_connect(struct socket *sock,
+                                  struct sockaddr *address, int addrlen)
+{
+        int err;
+        struct sock *sk = sock->sk;
+
+        err = selinux_socket_connect_helper(sock, address, addrlen);
+        if (err)
+                return err;
+
+        return selinux_netlbl_socket_connect(sk, address);
 }
 
 static int selinux_socket_listen(struct socket *sock, int backlog)
@@ -4830,7 +4903,8 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *op
         u32 peer_sid = SECSID_NULL;
 
         if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
-            sksec->sclass == SECCLASS_TCP_SOCKET)
+            sksec->sclass == SECCLASS_TCP_SOCKET ||
+            sksec->sclass == SECCLASS_SCTP_SOCKET)
                 peer_sid = sksec->peer_sid;
         if (peer_sid == SECSID_NULL)
                 return -ENOPROTOOPT;
@@ -4943,6 +5017,171 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
         sksec->sclass = isec->sclass;
 }
 
+/* Called whenever SCTP receives an INIT chunk. This happens when an incoming
+ * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
+ * already present).
+ */
+static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
+                                      struct sk_buff *skb)
+{
+        struct sk_security_struct *sksec = ep->base.sk->sk_security;
+        struct common_audit_data ad;
+        struct lsm_network_audit net = {0,};
+        u8 peerlbl_active;
+        u32 peer_sid = SECINITSID_UNLABELED;
+        u32 conn_sid;
+        int err = 0;
+
+        if (!selinux_policycap_extsockclass)
+                return 0;
+
+        peerlbl_active = selinux_peerlbl_enabled();
+
+        if (peerlbl_active) {
+                /* 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,
+                                              &peer_sid);
+                if (err)
+                        return err;
+
+                if (peer_sid == SECSID_NULL)
+                        peer_sid = SECINITSID_UNLABELED;
+        }
+
+        if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
+                sksec->sctp_assoc_state = SCTP_ASSOC_SET;
+
+                /* Here as first association on socket. As the peer SID
+                 * was allowed by peer recv (and the netif/node checks),
+                 * then it is approved by policy and used as the primary
+                 * peer SID for getpeercon(3).
+                 */
+                sksec->peer_sid = peer_sid;
+        } else if  (sksec->peer_sid != peer_sid) {
+                /* Other association peer SIDs are checked to enforce
+                 * consistency among the peer SIDs.
+                 */
+                ad.type = LSM_AUDIT_DATA_NET;
+                ad.u.net = &net;
+                ad.u.net->sk = ep->base.sk;
+                err = avc_has_perm(sksec->peer_sid, peer_sid, sksec->sclass,
+                                   SCTP_SOCKET__ASSOCIATION, &ad);
+                if (err)
+                        return err;
+        }
+
+        /* Compute the MLS component for the connection and store
+         * the information in ep. 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.
+         */
+        err = selinux_conn_sid(sksec->sid, peer_sid, &conn_sid);
+        if (err)
+                return err;
+
+        ep->secid = conn_sid;
+        ep->peer_secid = peer_sid;
+
+        /* Set any NetLabel labels including CIPSO/CALIPSO options. */
+        return selinux_netlbl_sctp_assoc_request(ep, skb);
+}
+
+/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
+ * based on their @optname.
+ */
+static int selinux_sctp_bind_connect(struct sock *sk, int optname,
+                                     struct sockaddr *address,
+                                     int addrlen)
+{
+        int len, err = 0, walk_size = 0;
+        void *addr_buf;
+        struct sockaddr *addr;
+        struct socket *sock;
+
+        if (!selinux_policycap_extsockclass)
+                return 0;
+
+        /* Process one or more addresses that may be IPv4 or IPv6 */
+        sock = sk->sk_socket;
+        addr_buf = address;
+
+        while (walk_size < addrlen) {
+                addr = addr_buf;
+                switch (addr->sa_family) {
+                case AF_INET:
+                        len = sizeof(struct sockaddr_in);
+                        break;
+                case AF_INET6:
+                        len = sizeof(struct sockaddr_in6);
+                        break;
+                default:
+                        return -EAFNOSUPPORT;
+                }
+
+                err = -EINVAL;
+                switch (optname) {
+                /* Bind checks */
+                case SCTP_PRIMARY_ADDR:
+                case SCTP_SET_PEER_PRIMARY_ADDR:
+                case SCTP_SOCKOPT_BINDX_ADD:
+                        err = selinux_socket_bind(sock, addr, len);
+                        break;
+                /* Connect checks */
+                case SCTP_SOCKOPT_CONNECTX:
+                case SCTP_PARAM_SET_PRIMARY:
+                case SCTP_PARAM_ADD_IP:
+                case SCTP_SENDMSG_CONNECT:
+                        err = selinux_socket_connect_helper(sock, addr, len);
+                        if (err)
+                                return err;
+
+                        /* As selinux_sctp_bind_connect() is called by the
+                         * SCTP protocol layer, the socket is already locked,
+                         * therefore selinux_netlbl_socket_connect_locked() is
+                         * is called here. The situations handled are:
+                         * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
+                         * whenever a new IP address is added or when a new
+                         * primary address is selected.
+                         * Note that an SCTP connect(2) call happens before
+                         * the SCTP protocol layer and is handled via
+                         * selinux_socket_connect().
+                         */
+                        err = selinux_netlbl_socket_connect_locked(sk, addr);
+                        break;
+                }
+
+                if (err)
+                        return err;
+
+                addr_buf += len;
+                walk_size += len;
+        }
+
+        return 0;
+}
+
+/* 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,
+                                  struct sock *newsk)
+{
+        struct sk_security_struct *sksec = sk->sk_security;
+        struct sk_security_struct *newsksec = newsk->sk_security;
+
+        /* If policy does not support SECCLASS_SCTP_SOCKET then call
+         * the non-sctp clone version.
+         */
+        if (!selinux_policycap_extsockclass)
+                return selinux_sk_clone_security(sk, newsk);
+
+        newsksec->sid = ep->secid;
+        newsksec->peer_sid = ep->peer_secid;
+        newsksec->sclass = sksec->sclass;
+        selinux_netlbl_sctp_sk_clone(sk, newsk);
+}
+
 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
                                      struct request_sock *req)
 {
@@ -6563,6 +6802,9 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
         LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
         LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
         LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
+        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(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),
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index acdee7795297..7f0372426494 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -176,7 +176,7 @@ struct security_class_mapping secclass_map[] = {
           { COMMON_CAP2_PERMS, NULL } },
         { "sctp_socket",
           { COMMON_SOCK_PERMS,
-            "node_bind", NULL } },
+            "node_bind", "name_connect", "association", NULL } },
         { "icmp_socket",
           { COMMON_SOCK_PERMS,
             "node_bind", NULL } },
diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h
index e77a5e307955..6ef4953431dc 100644
--- a/security/selinux/include/netlabel.h
+++ b/security/selinux/include/netlabel.h
@@ -32,6 +32,7 @@
 #include <linux/skbuff.h>
 #include <net/sock.h>
 #include <net/request_sock.h>
+#include <net/sctp/structs.h>
 
 #include "avc.h"
 #include "objsec.h"
@@ -52,9 +53,11 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
 int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
                                  u16 family,
                                  u32 sid);
-
+int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
+                                     struct sk_buff *skb);
 int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
 void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
+void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk);
 int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
                                 struct sk_buff *skb,
@@ -64,6 +67,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
                                      int level,
                                      int optname);
 int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr);
+int selinux_netlbl_socket_connect_locked(struct sock *sk,
+                                         struct sockaddr *addr);
 
 #else
 static inline void selinux_netlbl_cache_invalidate(void)
@@ -113,6 +118,11 @@ static inline int selinux_netlbl_conn_setsid(struct sock *sk,
         return 0;
 }
 
+static inline int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
+                                                    struct sk_buff *skb)
+{
+        return 0;
+}
 static inline int selinux_netlbl_inet_conn_request(struct request_sock *req,
                                                    u16 family)
 {
@@ -122,6 +132,10 @@ static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
 {
         return;
 }
+static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk, sock *newsk)
+{
+        return;
+}
 static inline int selinux_netlbl_socket_post_create(struct sock *sk,
                                                     u16 family)
 {
@@ -145,6 +159,11 @@ static inline int selinux_netlbl_socket_connect(struct sock *sk,
 {
         return 0;
 }
+static inline int selinux_netlbl_socket_connect_locked(struct sock *sk,
+                                                       struct sockaddr *addr)
+{
+        return 0;
+}
 #endif /* CONFIG_NETLABEL */
 
 #endif
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 3d54468ce334..dabf02888a95 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -130,6 +130,10 @@ struct sk_security_struct {
         u32 sid;                        /* SID of this object */
         u32 peer_sid;                   /* SID of peer */
         u16 sclass;                     /* sock security class */
+        enum {                          /* SCTP association state */
+                SCTP_ASSOC_UNSET = 0,
+                SCTP_ASSOC_SET,
+        } sctp_assoc_state;
 };
 
 struct tun_security_struct {
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 2c297b995b16..8730be427390 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -249,6 +249,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
         sk = skb_to_full_sk(skb);
         if (sk != NULL) {
                 struct sk_security_struct *sksec = sk->sk_security;
+
                 if (sksec->nlbl_state != NLBL_REQSKB)
                         return 0;
                 secattr = selinux_netlbl_sock_getattr(sk, sid);
@@ -270,6 +271,61 @@ skbuff_setsid_return:
 }
 
 /**
+ * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association.
+ * @ep: incoming association endpoint.
+ * @skb: the packet.
+ *
+ * Description:
+ * A new incoming connection is represented by @ep, ......
+ * Returns zero on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
+                                     struct sk_buff *skb)
+{
+        int rc;
+        struct netlbl_lsm_secattr secattr;
+        struct sk_security_struct *sksec = ep->base.sk->sk_security;
+        struct sockaddr *addr;
+        struct sockaddr_in addr4;
+#if IS_ENABLED(CONFIG_IPV6)
+        struct sockaddr_in6 addr6;
+#endif
+
+        if (ep->base.sk->sk_family != PF_INET &&
+                                ep->base.sk->sk_family != PF_INET6)
+                return 0;
+
+        netlbl_secattr_init(&secattr);
+        rc = security_netlbl_sid_to_secattr(ep->secid, &secattr);
+        if (rc != 0)
+                goto assoc_request_return;
+
+        /* Move skb hdr address info to a struct sockaddr and then call
+         * netlbl_conn_setattr().
+         */
+        if (ip_hdr(skb)->version == 4) {
+                addr4.sin_family = AF_INET;
+                addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
+                addr = (struct sockaddr *)&addr4;
+#if IS_ENABLED(CONFIG_IPV6)
+        } else {
+                addr6.sin6_family = AF_INET6;
+                addr6.sin6_addr = ipv6_hdr(skb)->saddr;
+                addr = (struct sockaddr *)&addr6;
+#endif
+        }
+
+        rc = netlbl_conn_setattr(ep->base.sk, addr, &secattr);
+        if (rc == 0)
+                sksec->nlbl_state = NLBL_LABELED;
+
+assoc_request_return:
+        netlbl_secattr_destroy(&secattr);
+        return rc;
+}
+
+/**
  * selinux_netlbl_inet_conn_request - Label an incoming stream connection
  * @req: incoming connection request socket
  *
@@ -319,6 +375,22 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
 }
 
 /**
+ * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
+ * @sk: current sock
+ * @newsk: the new sock
+ *
+ * Description:
+ * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
+ */
+void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
+{
+        struct sk_security_struct *sksec = sk->sk_security;
+        struct sk_security_struct *newsksec = newsk->sk_security;
+
+        newsksec->nlbl_state = sksec->nlbl_state;
+}
+
+/**
  * selinux_netlbl_socket_post_create - Label a socket using NetLabel
  * @sock: the socket to label
  * @family: protocol family
@@ -469,7 +541,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
 }
 
 /**
- * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
+ * connect
  * @sk: the socket to label
  * @addr: the destination address
  *
@@ -478,18 +551,13 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
  * Returns zero values on success, negative values on failure.
  *
  */
-int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+static int selinux_netlbl_socket_connect_helper(struct sock *sk,
+                                                struct sockaddr *addr)
 {
         int rc;
         struct sk_security_struct *sksec = sk->sk_security;
         struct netlbl_lsm_secattr *secattr;
 
-        if (sksec->nlbl_state != NLBL_REQSKB &&
-            sksec->nlbl_state != NLBL_CONNLABELED)
-                return 0;
-
-        lock_sock(sk);
-
         /* connected sockets are allowed to disconnect when the address family
          * is set to AF_UNSPEC, if that is what is happening we want to reset
          * the socket */
@@ -497,18 +565,61 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
                 netlbl_sock_delattr(sk);
                 sksec->nlbl_state = NLBL_REQSKB;
                 rc = 0;
-                goto socket_connect_return;
+                return rc;
         }
         secattr = selinux_netlbl_sock_genattr(sk);
         if (secattr == NULL) {
                 rc = -ENOMEM;
-                goto socket_connect_return;
+                return rc;
         }
         rc = netlbl_conn_setattr(sk, addr, secattr);
         if (rc == 0)
                 sksec->nlbl_state = NLBL_CONNLABELED;
 
-socket_connect_return:
+        return rc;
+}
+
+/**
+ * selinux_netlbl_socket_connect_locked - Label a client-side socket on
+ * connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket that already has the socket locked
+ * with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect_locked(struct sock *sk,
+                                         struct sockaddr *addr)
+{
+        struct sk_security_struct *sksec = sk->sk_security;
+
+        if (sksec->nlbl_state != NLBL_REQSKB &&
+            sksec->nlbl_state != NLBL_CONNLABELED)
+                return 0;
+
+        return selinux_netlbl_socket_connect_helper(sk, addr);
+}
+
+/**
+ * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+        int rc;
+
+        lock_sock(sk);
+        rc = selinux_netlbl_socket_connect_locked(sk, addr);
         release_sock(sk);
+
         return rc;
 }