Merge tag 'selinux-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux updates from Paul Moore:
 "A bigger than usual pull request for SELinux, 13 patches (lucky!)
  along with a scary looking diffstat.

  Although if you look a bit closer, excluding the usual minor
  tweaks/fixes, there are really only two significant changes in this
  pull request: the addition of proper SELinux access controls for SCTP
  and the encapsulation of a lot of internal SELinux state.

  The SCTP changes are the result of a multi-month effort (maybe even a
  year or longer?) between the SELinux folks and the SCTP folks to add
  proper SELinux controls. A special thanks go to Richard for seeing
  this through and keeping the effort moving forward.

  The state encapsulation work is a bit of janitorial work that came out
  of some early work on SELinux namespacing. The question of namespacing
  is still an open one, but I believe there is some real value in the
  encapsulation work so we've split that out and are now sending that up
  to you"

* tag 'selinux-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: wrap AVC state
  selinux: wrap selinuxfs state
  selinux: fix handling of uninitialized selinux state in get_bools/classes
  selinux: Update SELinux SCTP documentation
  selinux: Fix ltp test connect-syscall failure
  selinux: rename the {is,set}_enforcing() functions
  selinux: wrap global selinux state
  selinux: fix typo in selinux_netlbl_sctp_sk_clone declaration
  selinux: Add SCTP support
  sctp: Add LSM hooks
  sctp: Add ip option support
  security: Add support for SCTP security hooks
  netlabel: If PF_INET6, check sk_buff ip header version

43 files changed, 2936 insertions, 1252 deletions

diff --git a/Documentation/security/LSM-sctp.rst b/Documentation/security/LSM-sctp.rst
new file mode 100644
index 000000000000..6e5a3925a860
--- /dev/null
+++ b/Documentation/security/LSM-sctp.rst
@@ -0,0 +1,175 @@
+SCTP LSM Support
+================
+
+For security module support, three SCTP specific hooks have been implemented::
+
+    security_sctp_assoc_request()
+    security_sctp_bind_connect()
+    security_sctp_sk_clone()
+
+Also the following security hook has been utilised::
+
+    security_inet_conn_established()
+
+The usage of these hooks are described below with the SELinux implementation
+described in ``Documentation/security/SELinux-sctp.rst``
+
+
+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.
+
+
+security_sctp_bind_connect()
+-----------------------------
+Passes one or more ipv4/ipv6 addresses to the security module for validation
+based on the ``@optname`` that will result in either a bind or connect
+service as shown in the permission check tables below.
+Returns 0 on success, error on failure.
+::
+
+    @sk      - Pointer to sock structure.
+    @optname - Name of the option to validate.
+    @address - One or more ipv4 / ipv6 addresses.
+    @addrlen - The total length of address(s). This is calculated on each
+               ipv4 or ipv6 address using sizeof(struct sockaddr_in) or
+               sizeof(struct sockaddr_in6).
+
+  ------------------------------------------------------------------
+  |                     BIND Type 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 Type 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       |
+  ------------------------------------------------------------------
+
+A summary of the ``@optname`` entries is as follows::
+
+    SCTP_SOCKOPT_BINDX_ADD - Allows additional bind addresses to be
+                             associated after (optionally) calling
+                             bind(3).
+                             sctp_bindx(3) adds a set of bind
+                             addresses on a socket.
+
+    SCTP_SOCKOPT_CONNECTX - Allows the allocation of multiple
+                            addresses for reaching a peer
+                            (multi-homed).
+                            sctp_connectx(3) initiates a connection
+                            on an SCTP socket using multiple
+                            destination addresses.
+
+    SCTP_SENDMSG_CONNECT  - Initiate a connection that is generated by a
+                            sendmsg(2) or sctp_sendmsg(3) on a new asociation.
+
+    SCTP_PRIMARY_ADDR     - Set local primary address.
+
+    SCTP_SET_PEER_PRIMARY_ADDR - Request peer sets address as
+                                 association primary.
+
+    SCTP_PARAM_ADD_IP          - These are used when Dynamic Address
+    SCTP_PARAM_SET_PRIMARY     - Reconfiguration is enabled as explained below.
+
+
+To support Dynamic Address Reconfiguration the following parameters must be
+enabled on both endpoints (or use the appropriate **setsockopt**\(2))::
+
+    /proc/sys/net/sctp/addip_enable
+    /proc/sys/net/sctp/addip_noauth_enable
+
+then the following *_PARAM_*'s are sent to the peer in an
+ASCONF chunk when the corresponding ``@optname``'s are present::
+
+          @optname                      ASCONF Parameter
+         ----------                    ------------------
+    SCTP_SOCKOPT_BINDX_ADD     ->   SCTP_PARAM_ADD_IP
+    SCTP_SET_PEER_PRIMARY_ADDR ->   SCTP_PARAM_SET_PRIMARY
+
+
+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).
+::
+
+    @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::
+
+    @sk  - pointer to sock structure.
+    @skb - pointer to skbuff of the COOKIE ACK packet.
+
+
+Security Hooks used for Association Establishment
+=================================================
+The following diagram shows the use of ``security_sctp_bind_connect()``,
+``security_sctp_assoc_request()``, ``security_inet_conn_established()`` when
+establishing an association.
+::
+
+      SCTP endpoint "A"                                SCTP endpoint "Z"
+      =================                                =================
+    sctp_sf_do_prm_asoc()
+ Association setup can be initiated
+ by a connect(2), sctp_connectx(3),
+ sendmsg(2) or sctp_sendmsg(3).
+ These will result in a call to
+ security_sctp_bind_connect() to
+ initiate an association to
+ SCTP peer endpoint "Z".
+         INIT --------------------------------------------->
+                                                   sctp_sf_do_5_1B_init()
+                                                 Respond to an INIT chunk.
+                                             SCTP peer endpoint "A" is
+                                             asking for an association. Call
+                                             security_sctp_assoc_request()
+                                             to set the peer label if first
+                                             association.
+                                             If not first association, check
+                                             whether allowed, IF so send:
+          <----------------------------------------------- INIT ACK
+          |                                  ELSE audit event and silently
+          |                                       discard the packet.
+          |
+    COOKIE ECHO ------------------------------------------>
+                                                          |
+                                                          |
+                                                          |
+          <------------------------------------------- COOKIE ACK
+          |                                               |
+    sctp_sf_do_5_1E_ca                                    |
+ Call security_inet_conn_established()                    |
+ to set the peer label.                                   |
+          |                                               |
+          |                               If SCTP_SOCKET_TCP or peeled off
+          |                               socket security_sctp_sk_clone() is
+          |                               called to clone the new socket.
+          |                                               |
+      ESTABLISHED                                    ESTABLISHED
+          |                                               |
+    ------------------------------------------------------------------
+    |                     Association Established                    |
+    ------------------------------------------------------------------
+
+
diff --git a/Documentation/security/SELinux-sctp.rst b/Documentation/security/SELinux-sctp.rst
new file mode 100644
index 000000000000..a332cb1c5334
--- /dev/null
+++ b/Documentation/security/SELinux-sctp.rst
@@ -0,0 +1,158 @@
+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. Any further
+associations on this socket will have their packet peer label compared to
+the sockets peer label, and only if they are different will the
+``association`` permission be validated. This is 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/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index bde167fa2c51..6e6951b42be5 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -906,6 +906,33 @@
  *	associated with the TUN device's security structure.
  *	@security pointer to the TUN devices's security structure.
  *
+ * Security hooks for SCTP
+ *
+ * @sctp_assoc_request:
+ *	Passes the @ep and @chunk->skb of the association INIT packet to
+ *	the security module.
+ *	@ep pointer to sctp endpoint structure.
+ *	@skb pointer to skbuff of association packet.
+ *	Return 0 on success, error on failure.
+ * @sctp_bind_connect:
+ *	Validiate permissions required for each address associated with sock
+ *	@sk. Depending on @optname, the addresses will be treated as either
+ *	for a connect or bind service. The @addrlen is calculated on each
+ *	ipv4 and ipv6 address using sizeof(struct sockaddr_in) or
+ *	sizeof(struct sockaddr_in6).
+ *	@sk pointer to sock structure.
+ *	@optname name of the option to validate.
+ *	@address list containing one or more ipv4/ipv6 addresses.
+ *	@addrlen total length of address(s).
+ *	Return 0 on success, error on failure.
+ * @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).
+ *	@ep pointer to current sctp endpoint structure.
+ *	@sk pointer to current sock structure.
+ *	@sk pointer to new sock structure.
+ *
  * Security hooks for Infiniband
  *
  * @ib_pkey_access:
@@ -1665,6 +1692,12 @@ union security_list_options {
 	int (*tun_dev_attach_queue)(void *security);
 	int (*tun_dev_attach)(struct sock *sk, void *security);
 	int (*tun_dev_open)(void *security);
+	int (*sctp_assoc_request)(struct sctp_endpoint *ep,
+				  struct sk_buff *skb);
+	int (*sctp_bind_connect)(struct sock *sk, int optname,
+				 struct sockaddr *address, int addrlen);
+	void (*sctp_sk_clone)(struct sctp_endpoint *ep, struct sock *sk,
+			      struct sock *newsk);
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_INFINIBAND
@@ -1914,6 +1947,9 @@ struct security_hook_heads {
 	struct list_head tun_dev_attach_queue;
 	struct list_head tun_dev_attach;
 	struct list_head tun_dev_open;
+	struct list_head sctp_assoc_request;
+	struct list_head sctp_bind_connect;
+	struct list_head sctp_sk_clone;
 #endif	/* CONFIG_SECURITY_NETWORK */
 #ifdef CONFIG_SECURITY_INFINIBAND
 	struct list_head ib_pkey_access;
diff --git a/include/linux/security.h b/include/linux/security.h
index 128e1e4a5346..17ffd1ef6074 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -112,6 +112,7 @@ struct xfrm_policy;
 struct xfrm_state;
 struct xfrm_user_sec_ctx;
 struct seq_file;
+struct sctp_endpoint;
 
 #ifdef CONFIG_MMU
 extern unsigned long mmap_min_addr;
@@ -1226,6 +1227,11 @@ int security_tun_dev_create(void);
 int security_tun_dev_attach_queue(void *security);
 int security_tun_dev_attach(struct sock *sk, void *security);
 int security_tun_dev_open(void *security);
+int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb);
+int security_sctp_bind_connect(struct sock *sk, int optname,
+			       struct sockaddr *address, int addrlen);
+void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
+			    struct sock *newsk);
 
 #else	/* CONFIG_SECURITY_NETWORK */
 static inline int security_unix_stream_connect(struct sock *sock,
@@ -1418,6 +1424,25 @@ static inline int security_tun_dev_open(void *security)
 {
 	return 0;
 }
+
+static inline int security_sctp_assoc_request(struct sctp_endpoint *ep,
+					      struct sk_buff *skb)
+{
+	return 0;
+}
+
+static inline int security_sctp_bind_connect(struct sock *sk, int optname,
+					     struct sockaddr *address,
+					     int addrlen)
+{
+	return 0;
+}
+
+static inline void security_sctp_sk_clone(struct sctp_endpoint *ep,
+					  struct sock *sk,
+					  struct sock *newsk)
+{
+}
 #endif	/* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_INFINIBAND
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 72c5b8fc3232..28b996d63490 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -432,9 +432,11 @@ static inline int sctp_list_single_entry(struct list_head *head)
 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 {
 	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
+	struct sctp_af *af = sp->pf->af;
 	int frag = pmtu;
 
-	frag -= sp->pf->af->net_header_len;
+	frag -= af->ip_options_len(asoc->base.sk);
+	frag -= af->net_header_len;
 	frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream);
 
 	if (asoc->user_frag)
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index c63249ea34c3..a0ec462bc1a9 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -491,6 +491,7 @@ struct sctp_af {
 	void		(*ecn_capable)(struct sock *sk);
 	__u16		net_header_len;
 	int		sockaddr_len;
+	int		(*ip_options_len)(struct sock *sk);
 	sa_family_t	sa_family;
 	struct list_head list;
 };
@@ -515,6 +516,7 @@ struct sctp_pf {
 	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
 	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
 	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
+	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
 	struct sctp_af *af;
 };
 
@@ -1320,6 +1322,16 @@ struct sctp_endpoint {
 	      reconf_enable:1;
 
 	__u8  strreset_enable;
+
+	/* Security identifiers from incoming (INIT). These are set by
+	 * security_sctp_assoc_request(). These will only be used by
+	 * SCTP TCP type sockets and peeled off connections as they
+	 * cause a new socket to be generated. security_sctp_sk_clone()
+	 * will then plug these into the new socket.
+	 */
+
+	u32 secid;
+	u32 peer_secid;
 };
 
 /* Recover the outter endpoint structure. */
diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index afd4346386e0..b64d583bf053 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -127,6 +127,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_STREAM_SCHEDULER	123
 #define SCTP_STREAM_SCHEDULER_VALUE	124
 #define SCTP_INTERLEAVING_SUPPORTED	125
+#define SCTP_SENDMSG_CONNECT	126
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE	0x0000
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 22dc1b9d6362..c070dfc0190a 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1472,6 +1472,16 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 		iface = rcu_dereference(netlbl_unlhsh_def);
 	if (iface == NULL || !iface->valid)
 		goto unlabel_getattr_nolabel;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	/* When resolving a fallback label, check the sk_buff version as
+	 * it is possible (e.g. SCTP) to have family = PF_INET6 while
+	 * receiving ip_hdr(skb)->version = 4.
+	 */
+	if (family == PF_INET6 && ip_hdr(skb)->version == 4)
+		family = PF_INET;
+#endif /* IPv6 */
+
 	switch (family) {
 	case PF_INET: {
 		struct iphdr *hdr4;
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index f889a84f264d..be296d633e95 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -172,6 +172,8 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 	struct list_head *pos, *temp;
 	struct sctp_chunk *chunk;
 	struct sctp_datamsg *msg;
+	struct sctp_sock *sp;
+	struct sctp_af *af;
 	int err;
 
 	msg = sctp_datamsg_new(GFP_KERNEL);
@@ -190,9 +192,11 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 	/* This is the biggest possible DATA chunk that can fit into
 	 * the packet
 	 */
-	max_data = asoc->pathmtu -
-		   sctp_sk(asoc->base.sk)->pf->af->net_header_len -
-		   sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream);
+	sp = sctp_sk(asoc->base.sk);
+	af = sp->pf->af;
+	max_data = asoc->pathmtu - af->net_header_len -
+		   sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream) -
+		   af->ip_options_len(asoc->base.sk);
 	max_data = SCTP_TRUNC4(max_data);
 
 	/* If the the peer requested that we authenticate DATA chunks
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 0d873c58e516..6dd976c8ab61 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -427,6 +427,41 @@ static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 	rcu_read_unlock();
 }
 
+/* Copy over any ip options */
+static void sctp_v6_copy_ip_options(struct sock *sk, struct so