Message-ID: <1511897940.30337.25.camel@tycho.nsa.gov>
Date:   Tue, 28 Nov 2017 14:39:00 -0500
From:   Stephen Smalley <sds@...ho.nsa.gov>
To:     Richard Haines <richard_c_haines@...nternet.com>,
        selinux@...ho.nsa.gov, netdev@...r.kernel.org,
        linux-sctp@...r.kernel.org, linux-security-module@...r.kernel.org
Cc:     marcelo.leitner@...il.com, nhorman@...driver.com,
        vyasevich@...il.com
Subject: Re: [PATCH 4/4] selinux: Add SCTP support

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@...nternet.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 ``@...name
> `` 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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