[4/4] selinux: Add SCTP support
diff mbox

Message ID 20171127193217.2768-1-richard_c_haines@btinternet.com
State New
Headers show

Commit Message

Richard Haines Nov. 27, 2017, 7:32 p.m. UTC
The SELinux SCTP implementation is explained in:
Documentation/security/SELinux-sctp.rst

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
---
 Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
 security/selinux/hooks.c                | 278 +++++++++++++++++++++++++++++---
 security/selinux/include/classmap.h     |   2 +-
 security/selinux/include/netlabel.h     |  15 +-
 security/selinux/include/objsec.h       |   4 +
 security/selinux/netlabel.c             | 128 +++++++++++++--
 6 files changed, 499 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/security/SELinux-sctp.rst

Comments

Stephen Smalley Nov. 28, 2017, 7:39 p.m. UTC | #1
On Mon, 2017-11-27 at 19:32 +0000, Richard Haines wrote:
> The SELinux SCTP implementation is explained in:
> Documentation/security/SELinux-sctp.rst
> 
> Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
> ---
>  Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
>  security/selinux/hooks.c                | 278
> +++++++++++++++++++++++++++++---
>  security/selinux/include/classmap.h     |   2 +-
>  security/selinux/include/netlabel.h     |  15 +-
>  security/selinux/include/objsec.h       |   4 +
>  security/selinux/netlabel.c             | 128 +++++++++++++--
>  6 files changed, 499 insertions(+), 32 deletions(-)
>  create mode 100644 Documentation/security/SELinux-sctp.rst
> 
> diff --git a/Documentation/security/SELinux-sctp.rst
> b/Documentation/security/SELinux-sctp.rst
> new file mode 100644
> index 0000000..f6a9162
> --- /dev/null
> +++ b/Documentation/security/SELinux-sctp.rst
> @@ -0,0 +1,104 @@
> +SCTP SELinux Support
> +=====================
> +
> +Security Hooks
> +===============
> +
> +The ``Documentation/security/LSM-sctp.rst`` document describes how
> the
> +following sctp security hooks are utilised::
> +
> +    security_sctp_assoc_request()
> +    security_sctp_bind_connect()
> +    security_sctp_sk_clone()
> +    security_inet_conn_established()
> +
> +
> +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 Bind, Connect and ASCONF Chunk Parameter Permission Checks
> +================================================================
> +The hook ``security_sctp_bind_connect()`` is called by SCTP to check
> +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       |
> +  ------------------------------------------------------------------
> +
> +
> +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/b
> log/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 0110bb5..7bd5886 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 */
> @@ -4136,6 +4138,23 @@ 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;
>  	}
> @@ -4209,6 +4228,19 @@ 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;
> @@ -4398,6 +4430,10 @@ 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;

Same comment as before:
What prevents this from interleaving with selinux_sctp_assoc_request()
accesses to sksec->sctp_assoc_state?  You aren't holding any lock here.
 What ensures that this executes before selinux_sctp_assoc_request()?

> +
>  		err = selinux_netlbl_socket_post_create(sock->sk,
> family);
>  	}
>  
> @@ -4418,11 +4454,7 @@ 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;
> @@ -4434,7 +4466,13 @@ 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;
> @@ -4488,6 +4526,10 @@ 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;
> @@ -4502,7 +4544,7 @@ 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;
> @@ -4516,7 +4558,11 @@ static int selinux_socket_bind(struct socket
> *sock, struct sockaddr *address, in
>  	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;
> @@ -4527,10 +4573,12 @@ 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;
> @@ -4538,7 +4586,12 @@ 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;
> @@ -4552,10 +4605,19 @@ 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;
> @@ -4563,13 +4625,24 @@ 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)
> @@ -4832,7 +4905,8 @@ 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;
> @@ -4945,6 +5019,169 @@ 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).
> + * The lock is to ensure sksec->sctp_assoc_state.
> + */
> +static DEFINE_SPINLOCK(assoc_lock);

The lock needs to be taken by all entities accessing sksec-
>sctp_assoc_state, and you need to further ensure proper handling if
the ordering is reversed.  Also, the lock should be per-sksec, not
global.

> +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;
> +
> +	spin_lock(&assoc_lock);
> +
> +	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)
> +			goto 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)
> +			goto 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)
> +		goto err;
> +
> +	ep->secid = conn_sid;
> +	ep->peer_secid = peer_sid;
> +
> +	/* Set any NetLabel labels including CIPSO/CALIPSO options.
> */
> +	err = selinux_netlbl_sctp_assoc_request(ep, skb);
> +
> +err:
> +	spin_unlock(&assoc_lock);
> +	return err;
> +}
> +
> +/*
> + * 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;
> +
> +			err = selinux_netlbl_sctp_socket_connect(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;
> +	newsksec->nlbl_state = sksec->nlbl_state;
> +}
> +
>  static int selinux_inet_conn_request(struct sock *sk, struct sk_buff
> *skb,
>  				     struct request_sock *req)
>  {
> @@ -6433,6 +6670,9 @@ 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 35ffb29..099065e 100644
> --- a/security/selinux/include/classmap.h
> +++ b/security/selinux/include/classmap.h
> @@ -175,7 +175,7 @@ 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 75686d5..313c8bd 100644
> --- a/security/selinux/include/netlabel.h
> +++ b/security/selinux/include/netlabel.h
> @@ -33,6 +33,7 @@
>  #include <linux/skbuff.h>
>  #include <net/sock.h>
>  #include <net/request_sock.h>
> +#include <net/sctp/structs.h>
>  
>  #include "avc.h"
>  #include "objsec.h"
> @@ -53,7 +54,8 @@ 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);
>  int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
> @@ -65,6 +67,7 @@ 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_sctp_socket_connect(struct sock *sk, struct
> sockaddr *addr);
>  
>  #else
>  static inline void selinux_netlbl_cache_invalidate(void)
> @@ -114,6 +117,11 @@ 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)
>  {
> @@ -146,6 +154,11 @@ static inline int
> selinux_netlbl_socket_connect(struct sock *sk,
>  {
>  	return 0;
>  }
> +static inline int selinux_netlbl_sctp_socket_connect(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 6ebc61e..e319d5d 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 aaba667..ac23f29 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -250,6 +250,7 @@ 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 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff
> *skb,
>  	return rc;
>  }
>  
> +/**
> + * 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
> @@ -470,7 +526,8 @@ 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
>   *
> @@ -479,18 +536,13 @@ 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 */
> @@ -498,18 +550,72 @@ 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 - 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;
> +	struct sk_security_struct *sksec = sk->sk_security;
> +
> +	if (sksec->nlbl_state != NLBL_REQSKB &&
> +	    sksec->nlbl_state != NLBL_CONNLABELED)
> +		return 0;
> +
> +	lock_sock(sk);
> +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
>  	release_sock(sk);
> +
> +	return rc;
> +}
> +
> +/**
> + * selinux_netlbl_sctp_socket_connect - Label an SCTP client-side
> socket on a
> + * connect
> + * @sk: the socket to label
> + * @addr: the destination address
> + *
> + * Description:
> + * Attempt to label a connected socket with NetLabel using the given
> address
> + * when called by the SCTP protocol layer. 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_netlbl_socket_connect()
> + * Returns zero values on success, negative values on failure.
> + *
> + */
> +int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct
> sockaddr *addr)
> +{
> +	int rc;
> +	struct sk_security_struct *sksec = sk->sk_security;
> +
> +	if (sksec->nlbl_state != NLBL_REQSKB &&
> +	    sksec->nlbl_state != NLBL_CONNLABELED)
> +		return 0;
> +
> +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
> +
>  	return rc;
>  }
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Stephen Smalley Nov. 28, 2017, 7:59 p.m. UTC | #2
On Tue, 2017-11-28 at 14:39 -0500, Stephen Smalley wrote:
> On Mon, 2017-11-27 at 19:32 +0000, Richard Haines wrote:
> > The SELinux SCTP implementation is explained in:
> > Documentation/security/SELinux-sctp.rst
> > 
> > Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
> > ---
> >  Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
> >  security/selinux/hooks.c                | 278
> > +++++++++++++++++++++++++++++---
> >  security/selinux/include/classmap.h     |   2 +-
> >  security/selinux/include/netlabel.h     |  15 +-
> >  security/selinux/include/objsec.h       |   4 +
> >  security/selinux/netlabel.c             | 128 +++++++++++++--
> >  6 files changed, 499 insertions(+), 32 deletions(-)
> >  create mode 100644 Documentation/security/SELinux-sctp.rst
> > 
> > diff --git a/Documentation/security/SELinux-sctp.rst
> > b/Documentation/security/SELinux-sctp.rst
> > new file mode 100644
> > index 0000000..f6a9162
> > --- /dev/null
> > +++ b/Documentation/security/SELinux-sctp.rst
> > @@ -0,0 +1,104 @@
> > +SCTP SELinux Support
> > +=====================
> > +
> > +Security Hooks
> > +===============
> > +
> > +The ``Documentation/security/LSM-sctp.rst`` document describes how
> > the
> > +following sctp security hooks are utilised::
> > +
> > +    security_sctp_assoc_request()
> > +    security_sctp_bind_connect()
> > +    security_sctp_sk_clone()
> > +    security_inet_conn_established()
> > +
> > +
> > +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 Bind, Connect and ASCONF Chunk Parameter Permission Checks
> > +================================================================
> > +The hook ``security_sctp_bind_connect()`` is called by SCTP to
> > check
> > +permissions required for ipv4/ipv6 addresses based on the ``@optna
> > me
> > `` 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       |
> > +  --------------------------------------------------------------
> > ----
> > +
> > +
> > +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
> > /b
> > log/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 0110bb5..7bd5886 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 */
> > @@ -4136,6 +4138,23 @@ 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;
> >  	}
> > @@ -4209,6 +4228,19 @@ 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;
> > @@ -4398,6 +4430,10 @@ 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;
> 
> Same comment as before:
> What prevents this from interleaving with
> selinux_sctp_assoc_request()
> accesses to sksec->sctp_assoc_state?  You aren't holding any lock
> here.
>  What ensures that this executes before selinux_sctp_assoc_request()?

Sorry, maybe I'm wrong. selinux_sctp_assoc_request() can't be called
until after bind() and listen() have completed?

> 
> > +
> >  		err = selinux_netlbl_socket_post_create(sock->sk,
> > family);
> >  	}
> >  
> > @@ -4418,11 +4454,7 @@ 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;
> > @@ -4434,7 +4466,13 @@ 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;
> > @@ -4488,6 +4526,10 @@ 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;
> > @@ -4502,7 +4544,7 @@ 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;
> > @@ -4516,7 +4558,11 @@ static int selinux_socket_bind(struct socket
> > *sock, struct sockaddr *address, in
> >  	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;
> > @@ -4527,10 +4573,12 @@ 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;
> > @@ -4538,7 +4586,12 @@ 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;
> > @@ -4552,10 +4605,19 @@ 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;
> > @@ -4563,13 +4625,24 @@ 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)
> > @@ -4832,7 +4905,8 @@ 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;
> > @@ -4945,6 +5019,169 @@ 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).
> > + * The lock is to ensure sksec->sctp_assoc_state.
> > + */
> > +static DEFINE_SPINLOCK(assoc_lock);
> 
> The lock needs to be taken by all entities accessing sksec-
> > sctp_assoc_state, and you need to further ensure proper handling if
> 
> the ordering is reversed.  Also, the lock should be per-sksec, not
> global.
> 
> > +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;
> > +
> > +	spin_lock(&assoc_lock);

So what is this protecting?  And if needed, does it need to be
spin_lock_bh() instead of just spin_lock()? Can multiple calls to
selinux_sctp_assoc_request() on the same endpoint be interleaved?

> > +
> > +	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)
> > +			goto 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)
> > +			goto 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)
> > +		goto err;
> > +
> > +	ep->secid = conn_sid;
> > +	ep->peer_secid = peer_sid;
> > +
> > +	/* Set any NetLabel labels including CIPSO/CALIPSO
> > options.
> > */
> > +	err = selinux_netlbl_sctp_assoc_request(ep, skb);
> > +
> > +err:
> > +	spin_unlock(&assoc_lock);
> > +	return err;
> > +}
> > +
> > +/*
> > + * 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;
> > +
> > +			err =
> > selinux_netlbl_sctp_socket_connect(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;
> > +	newsksec->nlbl_state = sksec->nlbl_state;
> > +}
> > +
> >  static int selinux_inet_conn_request(struct sock *sk, struct
> > sk_buff
> > *skb,
> >  				     struct request_sock *req)
> >  {
> > @@ -6433,6 +6670,9 @@ 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 35ffb29..099065e 100644
> > --- a/security/selinux/include/classmap.h
> > +++ b/security/selinux/include/classmap.h
> > @@ -175,7 +175,7 @@ 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 75686d5..313c8bd 100644
> > --- a/security/selinux/include/netlabel.h
> > +++ b/security/selinux/include/netlabel.h
> > @@ -33,6 +33,7 @@
> >  #include <linux/skbuff.h>
> >  #include <net/sock.h>
> >  #include <net/request_sock.h>
> > +#include <net/sctp/structs.h>
> >  
> >  #include "avc.h"
> >  #include "objsec.h"
> > @@ -53,7 +54,8 @@ 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);
> >  int selinux_netlbl_socket_post_create(struct sock *sk, u16
> > family);
> > @@ -65,6 +67,7 @@ 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_sctp_socket_connect(struct sock *sk, struct
> > sockaddr *addr);
> >  
> >  #else
> >  static inline void selinux_netlbl_cache_invalidate(void)
> > @@ -114,6 +117,11 @@ 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)
> >  {
> > @@ -146,6 +154,11 @@ static inline int
> > selinux_netlbl_socket_connect(struct sock *sk,
> >  {
> >  	return 0;
> >  }
> > +static inline int selinux_netlbl_sctp_socket_connect(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 6ebc61e..e319d5d 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 aaba667..ac23f29 100644
> > --- a/security/selinux/netlabel.c
> > +++ b/security/selinux/netlabel.c
> > @@ -250,6 +250,7 @@ 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 @@ int selinux_netlbl_skbuff_setsid(struct
> > sk_buff
> > *skb,
> >  	return rc;
> >  }
> >  
> > +/**
> > + * 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
> > @@ -470,7 +526,8 @@ 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
> >   *
> > @@ -479,18 +536,13 @@ 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 */
> > @@ -498,18 +550,72 @@ 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 - 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;
> > +	struct sk_security_struct *sksec = sk->sk_security;
> > +
> > +	if (sksec->nlbl_state != NLBL_REQSKB &&
> > +	    sksec->nlbl_state != NLBL_CONNLABELED)
> > +		return 0;
> > +
> > +	lock_sock(sk);
> > +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
> >  	release_sock(sk);
> > +
> > +	return rc;
> > +}
> > +
> > +/**
> > + * selinux_netlbl_sctp_socket_connect - Label an SCTP client-side
> > socket on a
> > + * connect
> > + * @sk: the socket to label
> > + * @addr: the destination address
> > + *
> > + * Description:
> > + * Attempt to label a connected socket with NetLabel using the
> > given
> > address
> > + * when called by the SCTP protocol layer. 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_netlbl_socket_connect()
> > + * Returns zero values on success, negative values on failure.
> > + *
> > + */
> > +int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct
> > sockaddr *addr)
> > +{
> > +	int rc;
> > +	struct sk_security_struct *sksec = sk->sk_security;
> > +
> > +	if (sksec->nlbl_state != NLBL_REQSKB &&
> > +	    sksec->nlbl_state != NLBL_CONNLABELED)
> > +		return 0;
> > +
> > +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
> > +
> >  	return rc;
> >  }
--
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kernel test robot Nov. 29, 2017, 6:08 p.m. UTC | #3
Hi Richard,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on security/next]
[cannot apply to net-next/master net/master v4.15-rc1 next-20171129]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Richard-Haines/Add-SELinux-SCTP-protocol-support/20171129-222900
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git next
config: x86_64-allyesdebian (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   security/selinux/hooks.c: In function 'selinux_sctp_sk_clone':
>> security/selinux/hooks.c:5185:10: error: 'struct sk_security_struct' has no member named 'nlbl_state'
     newsksec->nlbl_state = sksec->nlbl_state;
             ^~
   security/selinux/hooks.c:5185:30: error: 'struct sk_security_struct' has no member named 'nlbl_state'
     newsksec->nlbl_state = sksec->nlbl_state;
                                 ^~

vim +5185 security/selinux/hooks.c

  5168	
  5169	/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
  5170	static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
  5171					  struct sock *newsk)
  5172	{
  5173		struct sk_security_struct *sksec = sk->sk_security;
  5174		struct sk_security_struct *newsksec = newsk->sk_security;
  5175	
  5176		/* If policy does not support SECCLASS_SCTP_SOCKET then call
  5177		 * the non-sctp clone version.
  5178		 */
  5179		if (!selinux_policycap_extsockclass)
  5180			return selinux_sk_clone_security(sk, newsk);
  5181	
  5182		newsksec->sid = ep->secid;
  5183		newsksec->peer_sid = ep->peer_secid;
  5184		newsksec->sclass = sksec->sclass;
> 5185		newsksec->nlbl_state = sksec->nlbl_state;
  5186	}
  5187	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Richard Haines Dec. 4, 2017, 11:40 a.m. UTC | #4
On Tue, 2017-11-28 at 14:59 -0500, Stephen Smalley wrote:
> On Tue, 2017-11-28 at 14:39 -0500, Stephen Smalley wrote:
> > On Mon, 2017-11-27 at 19:32 +0000, Richard Haines wrote:
> > > The SELinux SCTP implementation is explained in:
> > > Documentation/security/SELinux-sctp.rst
> > > 
> > > Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
> > > ---
> > >  Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
> > >  security/selinux/hooks.c                | 278
> > > +++++++++++++++++++++++++++++---
> > >  security/selinux/include/classmap.h     |   2 +-
> > >  security/selinux/include/netlabel.h     |  15 +-
> > >  security/selinux/include/objsec.h       |   4 +
> > >  security/selinux/netlabel.c             | 128 +++++++++++++--
> > >  6 files changed, 499 insertions(+), 32 deletions(-)
> > >  create mode 100644 Documentation/security/SELinux-sctp.rst
> > > 
> > > diff --git a/Documentation/security/SELinux-sctp.rst
> > > b/Documentation/security/SELinux-sctp.rst
> > > new file mode 100644
> > > index 0000000..f6a9162
> > > --- /dev/null
> > > +++ b/Documentation/security/SELinux-sctp.rst
> > > @@ -0,0 +1,104 @@
> > > +SCTP SELinux Support
> > > +=====================
> > > +
> > > +Security Hooks
> > > +===============
> > > +
> > > +The ``Documentation/security/LSM-sctp.rst`` document describes
> > > how
> > > the
> > > +following sctp security hooks are utilised::
> > > +
> > > +    security_sctp_assoc_request()
> > > +    security_sctp_bind_connect()
> > > +    security_sctp_sk_clone()
> > > +    security_inet_conn_established()
> > > +
> > > +
> > > +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 Bind, Connect and ASCONF Chunk Parameter Permission Checks
> > > +================================================================
> > > +The hook ``security_sctp_bind_connect()`` is called by SCTP to
> > > check
> > > +permissions required for ipv4/ipv6 addresses based on the ``@opt
> > > na
> > > me
> > > `` 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       |
> > > +  --------------------------------------------------------------
> > > ----
> > > +
> > > +
> > > +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.c
> > > om
> > > /b
> > > log/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 0110bb5..7bd5886 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 */
> > > @@ -4136,6 +4138,23 @@ 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;
> > >  	}
> > > @@ -4209,6 +4228,19 @@ 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;
> > > @@ -4398,6 +4430,10 @@ 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;
> > 
> > Same comment as before:
> > What prevents this from interleaving with
> > selinux_sctp_assoc_request()
> > accesses to sksec->sctp_assoc_state?  You aren't holding any lock
> > here.
> >  What ensures that this executes before
> > selinux_sctp_assoc_request()?
> 
> Sorry, maybe I'm wrong. selinux_sctp_assoc_request() can't be called
> until after bind() and listen() have completed?
Correct - In tests I've never had a problem here.
> 
> > 
> > > +
> > >  		err = selinux_netlbl_socket_post_create(sock-
> > > >sk,
> > > family);
> > >  	}
> > >  
> > > @@ -4418,11 +4454,7 @@ 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;
> > > @@ -4434,7 +4466,13 @@ 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;
> > > @@ -4488,6 +4526,10 @@ 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;
> > > @@ -4502,7 +4544,7 @@ 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;
> > > @@ -4516,7 +4558,11 @@ static int selinux_socket_bind(struct
> > > socket
> > > *sock, struct sockaddr *address, in
> > >  	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;
> > > @@ -4527,10 +4573,12 @@ 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;
> > > @@ -4538,7 +4586,12 @@ 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;
> > > @@ -4552,10 +4605,19 @@ 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;
> > > @@ -4563,13 +4625,24 @@ 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)
> > > @@ -4832,7 +4905,8 @@ 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;
> > > @@ -4945,6 +5019,169 @@ 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).
> > > + * The lock is to ensure sksec->sctp_assoc_state.
> > > + */
> > > +static DEFINE_SPINLOCK(assoc_lock);
> > 
> > The lock needs to be taken by all entities accessing sksec-
> > > sctp_assoc_state, and you need to further ensure proper handling
> > > if
> > 
> > the ordering is reversed.  Also, the lock should be per-sksec, not
> > global.
> > 
> > > +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;
> > > +
> > > +	spin_lock(&assoc_lock);
> 
> So what is this protecting?  And if needed, does it need to be
> spin_lock_bh() instead of just spin_lock()? Can multiple calls to
> selinux_sctp_assoc_request() on the same endpoint be interleaved?
> 
In the RFC patch I would also call this on client side INIT_ACK which
is why I had the lock. However I've now dropped this check so the lock
can go. During tests I've not seen any interleaving so removing this
lock seems okay.

I'll submit a new patch to also include the kbuild test robot catch as
well later this week.

> > > +
> > > +	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)
> > > +			goto 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)
> > > +			goto 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)
> > > +		goto err;
> > > +
> > > +	ep->secid = conn_sid;
> > > +	ep->peer_secid = peer_sid;
> > > +
> > > +	/* Set any NetLabel labels including CIPSO/CALIPSO
> > > options.
> > > */
> > > +	err = selinux_netlbl_sctp_assoc_request(ep, skb);
> > > +
> > > +err:
> > > +	spin_unlock(&assoc_lock);
> > > +	return err;
> > > +}
> > > +
> > > +/*
> > > + * 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;
> > > +
> > > +			err =
> > > selinux_netlbl_sctp_socket_connect(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;
> > > +	newsksec->nlbl_state = sksec->nlbl_state;
> > > +}
> > > +
> > >  static int selinux_inet_conn_request(struct sock *sk, struct
> > > sk_buff
> > > *skb,
> > >  				     struct request_sock *req)
> > >  {
> > > @@ -6433,6 +6670,9 @@ 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 35ffb29..099065e 100644
> > > --- a/security/selinux/include/classmap.h
> > > +++ b/security/selinux/include/classmap.h
> > > @@ -175,7 +175,7 @@ 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 75686d5..313c8bd 100644
> > > --- a/security/selinux/include/netlabel.h
> > > +++ b/security/selinux/include/netlabel.h
> > > @@ -33,6 +33,7 @@
> > >  #include <linux/skbuff.h>
> > >  #include <net/sock.h>
> > >  #include <net/request_sock.h>
> > > +#include <net/sctp/structs.h>
> > >  
> > >  #include "avc.h"
> > >  #include "objsec.h"
> > > @@ -53,7 +54,8 @@ 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);
> > >  int selinux_netlbl_socket_post_create(struct sock *sk, u16
> > > family);
> > > @@ -65,6 +67,7 @@ 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_sctp_socket_connect(struct sock *sk, struct
> > > sockaddr *addr);
> > >  
> > >  #else
> > >  static inline void selinux_netlbl_cache_invalidate(void)
> > > @@ -114,6 +117,11 @@ 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)
> > >  {
> > > @@ -146,6 +154,11 @@ static inline int
> > > selinux_netlbl_socket_connect(struct sock *sk,
> > >  {
> > >  	return 0;
> > >  }
> > > +static inline int selinux_netlbl_sctp_socket_connect(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 6ebc61e..e319d5d 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 aaba667..ac23f29 100644
> > > --- a/security/selinux/netlabel.c
> > > +++ b/security/selinux/netlabel.c
> > > @@ -250,6 +250,7 @@ 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 @@ int selinux_netlbl_skbuff_setsid(struct
> > > sk_buff
> > > *skb,
> > >  	return rc;
> > >  }
> > >  
> > > +/**
> > > + * 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
> > > @@ -470,7 +526,8 @@ 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
> > >   *
> > > @@ -479,18 +536,13 @@ 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 */
> > > @@ -498,18 +550,72 @@ 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 - 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;
> > > +	struct sk_security_struct *sksec = sk->sk_security;
> > > +
> > > +	if (sksec->nlbl_state != NLBL_REQSKB &&
> > > +	    sksec->nlbl_state != NLBL_CONNLABELED)
> > > +		return 0;
> > > +
> > > +	lock_sock(sk);
> > > +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
> > >  	release_sock(sk);
> > > +
> > > +	return rc;
> > > +}
> > > +
> > > +/**
> > > + * selinux_netlbl_sctp_socket_connect - Label an SCTP client-
> > > side
> > > socket on a
> > > + * connect
> > > + * @sk: the socket to label
> > > + * @addr: the destination address
> > > + *
> > > + * Description:
> > > + * Attempt to label a connected socket with NetLabel using the
> > > given
> > > address
> > > + * when called by the SCTP protocol layer. 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_netlbl_socket_connect()
> > > + * Returns zero values on success, negative values on failure.
> > > + *
> > > + */
> > > +int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct
> > > sockaddr *addr)
> > > +{
> > > +	int rc;
> > > +	struct sk_security_struct *sksec = sk->sk_security;
> > > +
> > > +	if (sksec->nlbl_state != NLBL_REQSKB &&
> > > +	    sksec->nlbl_state != NLBL_CONNLABELED)
> > > +		return 0;
> > > +
> > > +	rc = selinux_netlbl_socket_connect_helper(sk, addr);
> > > +
> > >  	return rc;
> > >  }
> 
> --
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> security-module" in
> the body of a message to majordomo@vger.kernel.org
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Patch
diff mbox

diff --git a/Documentation/security/SELinux-sctp.rst b/Documentation/security/SELinux-sctp.rst
new file mode 100644
index 0000000..f6a9162
--- /dev/null
+++ b/Documentation/security/SELinux-sctp.rst
@@ -0,0 +1,104 @@ 
+SCTP SELinux Support
+=====================
+
+Security Hooks
+===============
+
+The ``Documentation/security/LSM-sctp.rst`` document describes how the
+following sctp security hooks are utilised::
+
+    security_sctp_assoc_request()
+    security_sctp_bind_connect()
+    security_sctp_sk_clone()
+    security_inet_conn_established()
+
+
+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 Bind, Connect and ASCONF Chunk Parameter Permission Checks
+================================================================
+The hook ``security_sctp_bind_connect()`` is called by SCTP to check
+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       |
+  ------------------------------------------------------------------
+
+
+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 0110bb5..7bd5886 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 */
@@ -4136,6 +4138,23 @@  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;
 	}
@@ -4209,6 +4228,19 @@  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;
@@ -4398,6 +4430,10 @@  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);
 	}
 
@@ -4418,11 +4454,7 @@  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;
@@ -4434,7 +4466,13 @@  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;
@@ -4488,6 +4526,10 @@  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;
@@ -4502,7 +4544,7 @@  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;
@@ -4516,7 +4558,11 @@  static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
 	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;
@@ -4527,10 +4573,12 @@  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;
@@ -4538,7 +4586,12 @@  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;
@@ -4552,10 +4605,19 @@  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;
@@ -4563,13 +4625,24 @@  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)
@@ -4832,7 +4905,8 @@  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;
@@ -4945,6 +5019,169 @@  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).
+ * The lock is to ensure sksec->sctp_assoc_state.
+ */
+static DEFINE_SPINLOCK(assoc_lock);
+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;
+
+	spin_lock(&assoc_lock);
+
+	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)
+			goto 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)
+			goto 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)
+		goto err;
+
+	ep->secid = conn_sid;
+	ep->peer_secid = peer_sid;
+
+	/* Set any NetLabel labels including CIPSO/CALIPSO options. */
+	err = selinux_netlbl_sctp_assoc_request(ep, skb);
+
+err:
+	spin_unlock(&assoc_lock);
+	return err;
+}
+
+/*
+ * 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;
+
+			err = selinux_netlbl_sctp_socket_connect(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;
+	newsksec->nlbl_state = sksec->nlbl_state;
+}
+
 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 				     struct request_sock *req)
 {
@@ -6433,6 +6670,9 @@  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 35ffb29..099065e 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -175,7 +175,7 @@  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 75686d5..313c8bd 100644
--- a/security/selinux/include/netlabel.h
+++ b/security/selinux/include/netlabel.h
@@ -33,6 +33,7 @@ 
 #include <linux/skbuff.h>
 #include <net/sock.h>
 #include <net/request_sock.h>
+#include <net/sctp/structs.h>
 
 #include "avc.h"
 #include "objsec.h"
@@ -53,7 +54,8 @@  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);
 int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
@@ -65,6 +67,7 @@  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_sctp_socket_connect(struct sock *sk, struct sockaddr *addr);
 
 #else
 static inline void selinux_netlbl_cache_invalidate(void)
@@ -114,6 +117,11 @@  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)
 {
@@ -146,6 +154,11 @@  static inline int selinux_netlbl_socket_connect(struct sock *sk,
 {
 	return 0;
 }
+static inline int selinux_netlbl_sctp_socket_connect(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 6ebc61e..e319d5d 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 aaba667..ac23f29 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -250,6 +250,7 @@  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 @@  int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
 	return rc;
 }
 
+/**
+ * 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
@@ -470,7 +526,8 @@  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
  *
@@ -479,18 +536,13 @@  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 */
@@ -498,18 +550,72 @@  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 - 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;
+	struct sk_security_struct *sksec = sk->sk_security;
+
+	if (sksec->nlbl_state != NLBL_REQSKB &&
+	    sksec->nlbl_state != NLBL_CONNLABELED)
+		return 0;
+
+	lock_sock(sk);
+	rc = selinux_netlbl_socket_connect_helper(sk, addr);
 	release_sock(sk);
+
+	return rc;
+}
+
+/**
+ * selinux_netlbl_sctp_socket_connect - Label an SCTP client-side socket on a
+ * connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address
+ * when called by the SCTP protocol layer. 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_netlbl_socket_connect()
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+	int rc;
+	struct sk_security_struct *sksec = sk->sk_security;
+
+	if (sksec->nlbl_state != NLBL_REQSKB &&
+	    sksec->nlbl_state != NLBL_CONNLABELED)
+		return 0;
+
+	rc = selinux_netlbl_socket_connect_helper(sk, addr);
+
 	return rc;
 }