new file mode 100644
@@ -0,0 +1,157 @@
+SCTP SELinux Support
+=====================
+
+Security Hooks
+===============
+
+``Documentation/security/LSM-sctp.rst`` describes the following SCTP security
+hooks with the SELinux specifics expanded below::
+
+ security_sctp_assoc_request()
+ security_sctp_bind_connect()
+ security_sctp_sk_clone()
+ security_inet_conn_established()
+
+
+security_sctp_assoc_request()
+-----------------------------
+Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the
+security module. Returns 0 on success, error on failure.
+::
+
+ @ep - pointer to sctp endpoint structure.
+ @skb - pointer to skbuff of association packet.
+
+The security module performs the following operations:
+ IF this is the first association on ``@ep->base.sk``, then set the peer
+ sid to that in ``@skb``. This will ensure there is only one peer sid
+ assigned to ``@ep->base.sk`` that may support multiple associations.
+
+ ELSE validate the ``@ep->base.sk peer_sid`` against the ``@skb peer sid``
+ to determine whether the association should be allowed or denied.
+
+ Set the sctp ``@ep sid`` to socket's sid (from ``ep->base.sk``) with
+ MLS portion taken from ``@skb peer sid``. This will be used by SCTP
+ TCP style sockets and peeled off connections as they cause a new socket
+ to be generated.
+
+ If IP security options are configured (CIPSO/CALIPSO), then the ip
+ options are set on the socket.
+
+
+security_sctp_bind_connect()
+-----------------------------
+Checks permissions required for ipv4/ipv6 addresses based on the ``@optname``
+as follows::
+
+ ------------------------------------------------------------------
+ | BIND Permission Checks |
+ | @optname | @address contains |
+ |----------------------------|-----------------------------------|
+ | SCTP_SOCKOPT_BINDX_ADD | One or more ipv4 / ipv6 addresses |
+ | SCTP_PRIMARY_ADDR | Single ipv4 or ipv6 address |
+ | SCTP_SET_PEER_PRIMARY_ADDR | Single ipv4 or ipv6 address |
+ ------------------------------------------------------------------
+
+ ------------------------------------------------------------------
+ | CONNECT Permission Checks |
+ | @optname | @address contains |
+ |----------------------------|-----------------------------------|
+ | SCTP_SOCKOPT_CONNECTX | One or more ipv4 / ipv6 addresses |
+ | SCTP_PARAM_ADD_IP | One or more ipv4 / ipv6 addresses |
+ | SCTP_SENDMSG_CONNECT | Single ipv4 or ipv6 address |
+ | SCTP_PARAM_SET_PRIMARY | Single ipv4 or ipv6 address |
+ ------------------------------------------------------------------
+
+
+``Documentation/security/LSM-sctp.rst`` gives a summary of the ``@optname``
+entries and also describes ASCONF chunk processing when Dynamic Address
+Reconfiguration is enabled.
+
+
+security_sctp_sk_clone()
+-------------------------
+Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style
+socket) or when a socket is 'peeled off' e.g userspace calls
+**sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new
+sockets sid and peer sid to that contained in the ``@ep sid`` and
+``@ep peer sid`` respectively.
+::
+
+ @ep - pointer to current sctp endpoint structure.
+ @sk - pointer to current sock structure.
+ @sk - pointer to new sock structure.
+
+
+security_inet_conn_established()
+---------------------------------
+Called when a COOKIE ACK is received where it sets the connection's peer sid
+to that in ``@skb``::
+
+ @sk - pointer to sock structure.
+ @skb - pointer to skbuff of the COOKIE ACK packet.
+
+
+Policy Statements
+==================
+The following class and permissions to support SCTP are available within the
+kernel::
+
+ class sctp_socket inherits socket { node_bind }
+
+whenever the following policy capability is enabled::
+
+ policycap extended_socket_class;
+
+SELinux SCTP support adds the ``name_connect`` permission for connecting
+to a specific port type and the ``association`` permission that is explained
+in the section below.
+
+If userspace tools have been updated, SCTP will support the ``portcon``
+statement as shown in the following example::
+
+ portcon sctp 1024-1036 system_u:object_r:sctp_ports_t:s0
+
+
+SCTP Peer Labeling
+===================
+An SCTP socket will only have one peer label assigned to it. This will be
+assigned during the establishment of the first association. Once the peer
+label has been assigned, any new associations will have the ``association``
+permission validated by checking the socket peer sid against the received
+packets peer sid to determine whether the association should be allowed or
+denied.
+
+NOTES:
+ 1) If peer labeling is not enabled, then the peer context will always be
+ ``SECINITSID_UNLABELED`` (``unlabeled_t`` in Reference Policy).
+
+ 2) As SCTP can support more than one transport address per endpoint
+ (multi-homing) on a single socket, it is possible to configure policy
+ and NetLabel to provide different peer labels for each of these. As the
+ socket peer label is determined by the first associations transport
+ address, it is recommended that all peer labels are consistent.
+
+ 3) **getpeercon**\(3) may be used by userspace to retrieve the sockets peer
+ context.
+
+ 4) While not SCTP specific, be aware when using NetLabel that if a label
+ is assigned to a specific interface, and that interface 'goes down',
+ then the NetLabel service will remove the entry. Therefore ensure that
+ the network startup scripts call **netlabelctl**\(8) to set the required
+ label (see **netlabel-config**\(8) helper script for details).
+
+ 5) The NetLabel SCTP peer labeling rules apply as discussed in the following
+ set of posts tagged "netlabel" at: http://www.paul-moore.com/blog/t.
+
+ 6) CIPSO is only supported for IPv4 addressing: ``socket(AF_INET, ...)``
+ CALIPSO is only supported for IPv6 addressing: ``socket(AF_INET6, ...)``
+
+ Note the following when testing CIPSO/CALIPSO:
+ a) CIPSO will send an ICMP packet if an SCTP packet cannot be
+ delivered because of an invalid label.
+ b) CALIPSO does not send an ICMP packet, just silently discards it.
+
+ 7) IPSEC is not supported as RFC 3554 - sctp/ipsec support has not been
+ implemented in userspace (**racoon**\(8) or **ipsec_pluto**\(8)),
+ although the kernel supports SCTP/IPSEC.
@@ -67,6 +67,8 @@
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/dccp.h>
+#include <linux/sctp.h>
+#include <net/sctp/structs.h>
#include <linux/quota.h>
#include <linux/un.h> /* for Unix socket types */
#include <net/af_unix.h> /* for Unix socket types */
@@ -4134,6 +4136,23 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
break;
}
+#if IS_ENABLED(CONFIG_IP_SCTP)
+ case IPPROTO_SCTP: {
+ struct sctphdr _sctph, *sh;
+
+ if (ntohs(ih->frag_off) & IP_OFFSET)
+ break;
+
+ offset += ihlen;
+ sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
+ if (sh == NULL)
+ break;
+
+ ad->u.net->sport = sh->source;
+ ad->u.net->dport = sh->dest;
+ break;
+ }
+#endif
default:
break;
}
@@ -4207,6 +4226,19 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
break;
}
+#if IS_ENABLED(CONFIG_IP_SCTP)
+ case IPPROTO_SCTP: {
+ struct sctphdr _sctph, *sh;
+
+ sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
+ if (sh == NULL)
+ break;
+
+ ad->u.net->sport = sh->source;
+ ad->u.net->dport = sh->dest;
+ break;
+ }
+#endif
/* includes fragments */
default:
break;
@@ -4396,6 +4428,10 @@ static int selinux_socket_post_create(struct socket *sock, int family,
sksec = sock->sk->sk_security;
sksec->sclass = sclass;
sksec->sid = sid;
+ /* Allows detection of the first association on this socket */
+ if (sksec->sclass == SECCLASS_SCTP_SOCKET)
+ sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
+
err = selinux_netlbl_socket_post_create(sock->sk, family);
}
@@ -4416,11 +4452,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
if (err)
goto out;
- /*
- * If PF_INET or PF_INET6, check name_bind permission for the port.
- * Multiple address binding for SCTP is not supported yet: we just
- * check the first address now.
- */
+ /* If PF_INET or PF_INET6, check name_bind permission for the port. */
family = sk->sk_family;
if (family == PF_INET || family == PF_INET6) {
char *addrp;
@@ -4432,7 +4464,13 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
unsigned short snum;
u32 sid, node_perm;
- if (family == PF_INET) {
+ /*
+ * sctp_bindx(3) calls via selinux_sctp_bind_connect()
+ * that validates multiple binding addresses. Because of this
+ * need to check address->sa_family as it is possible to have
+ * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
+ */
+ if (address->sa_family == AF_INET) {
if (addrlen < sizeof(struct sockaddr_in)) {
err = -EINVAL;
goto out;
@@ -4486,6 +4524,10 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
node_perm = DCCP_SOCKET__NODE_BIND;
break;
+ case SECCLASS_SCTP_SOCKET:
+ node_perm = SCTP_SOCKET__NODE_BIND;
+ break;
+
default:
node_perm = RAWIP_SOCKET__NODE_BIND;
break;
@@ -4500,7 +4542,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
ad.u.net->sport = htons(snum);
ad.u.net->family = family;
- if (family == PF_INET)
+ if (address->sa_family == AF_INET)
ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
else
ad.u.net->v6info.saddr = addr6->sin6_addr;
@@ -4514,7 +4556,11 @@ 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;
@@ -4525,10 +4571,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
return err;
/*
- * If a TCP or DCCP socket, check name_connect permission for the port.
+ * If a TCP, DCCP or SCTP socket, check name_connect permission
+ * for the port.
*/
if (sksec->sclass == SECCLASS_TCP_SOCKET ||
- sksec->sclass == SECCLASS_DCCP_SOCKET) {
+ sksec->sclass == SECCLASS_DCCP_SOCKET ||
+ sksec->sclass == SECCLASS_SCTP_SOCKET) {
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
struct sockaddr_in *addr4 = NULL;
@@ -4536,7 +4584,12 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
unsigned short snum;
u32 sid, perm;
- if (sk->sk_family == PF_INET) {
+ /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
+ * that validates multiple connect addresses. Because of this
+ * need to check address->sa_family as it is possible to have
+ * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
+ */
+ if (address->sa_family == AF_INET) {
addr4 = (struct sockaddr_in *)address;
if (addrlen < sizeof(struct sockaddr_in))
return -EINVAL;
@@ -4550,10 +4603,19 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
err = sel_netport_sid(sk->sk_protocol, snum, &sid);
if (err)
- goto out;
+ return err;
- perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
- TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
+ switch (sksec->sclass) {
+ case SECCLASS_TCP_SOCKET:
+ perm = TCP_SOCKET__NAME_CONNECT;
+ break;
+ case SECCLASS_DCCP_SOCKET:
+ perm = DCCP_SOCKET__NAME_CONNECT;
+ break;
+ case SECCLASS_SCTP_SOCKET:
+ perm = SCTP_SOCKET__NAME_CONNECT;
+ break;
+ }
ad.type = LSM_AUDIT_DATA_NET;
ad.u.net = &net;
@@ -4561,13 +4623,24 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
ad.u.net->family = sk->sk_family;
err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
if (err)
- goto out;
+ return err;
}
- err = selinux_netlbl_socket_connect(sk, address);
+ return 0;
+}
-out:
- return err;
+/* Supports connect(2), see comments in selinux_socket_connect_helper() */
+static int selinux_socket_connect(struct socket *sock,
+ struct sockaddr *address, int addrlen)
+{
+ int err;
+ struct sock *sk = sock->sk;
+
+ err = selinux_socket_connect_helper(sock, address, addrlen);
+ if (err)
+ return err;
+
+ return selinux_netlbl_socket_connect(sk, address);
}
static int selinux_socket_listen(struct socket *sock, int backlog)
@@ -4830,7 +4903,8 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *op
u32 peer_sid = SECSID_NULL;
if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
- sksec->sclass == SECCLASS_TCP_SOCKET)
+ sksec->sclass == SECCLASS_TCP_SOCKET ||
+ sksec->sclass == SECCLASS_SCTP_SOCKET)
peer_sid = sksec->peer_sid;
if (peer_sid == SECSID_NULL)
return -ENOPROTOOPT;
@@ -4943,6 +5017,171 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
sksec->sclass = isec->sclass;
}
+/* Called whenever SCTP receives an INIT chunk. This happens when an incoming
+ * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association
+ * already present).
+ */
+static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
+ struct sk_buff *skb)
+{
+ struct sk_security_struct *sksec = ep->base.sk->sk_security;
+ struct common_audit_data ad;
+ struct lsm_network_audit net = {0,};
+ u8 peerlbl_active;
+ u32 peer_sid = SECINITSID_UNLABELED;
+ u32 conn_sid;
+ int err = 0;
+
+ if (!selinux_policycap_extsockclass)
+ return 0;
+
+ peerlbl_active = selinux_peerlbl_enabled();
+
+ if (peerlbl_active) {
+ /* This will return peer_sid = SECSID_NULL if there are
+ * no peer labels, see security_net_peersid_resolve().
+ */
+ err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
+ &peer_sid);
+ if (err)
+ return err;
+
+ if (peer_sid == SECSID_NULL)
+ peer_sid = SECINITSID_UNLABELED;
+ }
+
+ if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
+ sksec->sctp_assoc_state = SCTP_ASSOC_SET;
+
+ /* Here as first association on socket. As the peer SID
+ * was allowed by peer recv (and the netif/node checks),
+ * then it is approved by policy and used as the primary
+ * peer SID for getpeercon(3).
+ */
+ sksec->peer_sid = peer_sid;
+ } else if (sksec->peer_sid != peer_sid) {
+ /* Other association peer SIDs are checked to enforce
+ * consistency among the peer SIDs.
+ */
+ ad.type = LSM_AUDIT_DATA_NET;
+ ad.u.net = &net;
+ ad.u.net->sk = ep->base.sk;
+ err = avc_has_perm(sksec->peer_sid, peer_sid, sksec->sclass,
+ SCTP_SOCKET__ASSOCIATION, &ad);
+ if (err)
+ return err;
+ }
+
+ /* Compute the MLS component for the connection and store
+ * the information in ep. This will be used by SCTP TCP type
+ * sockets and peeled off connections as they cause a new
+ * socket to be generated. selinux_sctp_sk_clone() will then
+ * plug this into the new socket.
+ */
+ err = selinux_conn_sid(sksec->sid, peer_sid, &conn_sid);
+ if (err)
+ return err;
+
+ ep->secid = conn_sid;
+ ep->peer_secid = peer_sid;
+
+ /* Set any NetLabel labels including CIPSO/CALIPSO options. */
+ return selinux_netlbl_sctp_assoc_request(ep, skb);
+}
+
+/* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
+ * based on their @optname.
+ */
+static int selinux_sctp_bind_connect(struct sock *sk, int optname,
+ struct sockaddr *address,
+ int addrlen)
+{
+ int len, err = 0, walk_size = 0;
+ void *addr_buf;
+ struct sockaddr *addr;
+ struct socket *sock;
+
+ if (!selinux_policycap_extsockclass)
+ return 0;
+
+ /* Process one or more addresses that may be IPv4 or IPv6 */
+ sock = sk->sk_socket;
+ addr_buf = address;
+
+ while (walk_size < addrlen) {
+ addr = addr_buf;
+ switch (addr->sa_family) {
+ case AF_INET:
+ len = sizeof(struct sockaddr_in);
+ break;
+ case AF_INET6:
+ len = sizeof(struct sockaddr_in6);
+ break;
+ default:
+ return -EAFNOSUPPORT;
+ }
+
+ err = -EINVAL;
+ switch (optname) {
+ /* Bind checks */
+ case SCTP_PRIMARY_ADDR:
+ case SCTP_SET_PEER_PRIMARY_ADDR:
+ case SCTP_SOCKOPT_BINDX_ADD:
+ err = selinux_socket_bind(sock, addr, len);
+ break;
+ /* Connect checks */
+ case SCTP_SOCKOPT_CONNECTX:
+ case SCTP_PARAM_SET_PRIMARY:
+ case SCTP_PARAM_ADD_IP:
+ case SCTP_SENDMSG_CONNECT:
+ err = selinux_socket_connect_helper(sock, addr, len);
+ if (err)
+ return err;
+
+ /* As selinux_sctp_bind_connect() is called by the
+ * SCTP protocol layer, the socket is already locked,
+ * therefore selinux_netlbl_socket_connect_locked() is
+ * is called here. The situations handled are:
+ * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
+ * whenever a new IP address is added or when a new
+ * primary address is selected.
+ * Note that an SCTP connect(2) call happens before
+ * the SCTP protocol layer and is handled via
+ * selinux_socket_connect().
+ */
+ err = selinux_netlbl_socket_connect_locked(sk, addr);
+ break;
+ }
+
+ if (err)
+ return err;
+
+ addr_buf += len;
+ walk_size += len;
+ }
+
+ return 0;
+}
+
+/* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
+static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
+ struct sock *newsk)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *newsksec = newsk->sk_security;
+
+ /* If policy does not support SECCLASS_SCTP_SOCKET then call
+ * the non-sctp clone version.
+ */
+ if (!selinux_policycap_extsockclass)
+ return selinux_sk_clone_security(sk, newsk);
+
+ newsksec->sid = ep->secid;
+ newsksec->peer_sid = ep->peer_secid;
+ newsksec->sclass = sksec->sclass;
+ selinux_netlbl_sctp_sk_clone(sk, newsk);
+}
+
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
@@ -6563,6 +6802,9 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
+ LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
+ LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
+ LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
@@ -176,7 +176,7 @@ struct security_class_mapping secclass_map[] = {
{ COMMON_CAP2_PERMS, NULL } },
{ "sctp_socket",
{ COMMON_SOCK_PERMS,
- "node_bind", NULL } },
+ "node_bind", "name_connect", "association", NULL } },
{ "icmp_socket",
{ COMMON_SOCK_PERMS,
"node_bind", NULL } },
@@ -32,6 +32,7 @@
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/request_sock.h>
+#include <net/sctp/structs.h>
#include "avc.h"
#include "objsec.h"
@@ -52,9 +53,11 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
u16 family,
u32 sid);
-
+int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
+ struct sk_buff *skb);
int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
+void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk);
int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
struct sk_buff *skb,
@@ -64,6 +67,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
int level,
int optname);
int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr);
+int selinux_netlbl_socket_connect_locked(struct sock *sk,
+ struct sockaddr *addr);
#else
static inline void selinux_netlbl_cache_invalidate(void)
@@ -113,6 +118,11 @@ static inline int selinux_netlbl_conn_setsid(struct sock *sk,
return 0;
}
+static inline int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
+ struct sk_buff *skb)
+{
+ return 0;
+}
static inline int selinux_netlbl_inet_conn_request(struct request_sock *req,
u16 family)
{
@@ -122,6 +132,10 @@ static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
{
return;
}
+static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk, sock *newsk)
+{
+ return;
+}
static inline int selinux_netlbl_socket_post_create(struct sock *sk,
u16 family)
{
@@ -145,6 +159,11 @@ static inline int selinux_netlbl_socket_connect(struct sock *sk,
{
return 0;
}
+static inline int selinux_netlbl_socket_connect_locked(struct sock *sk,
+ struct sockaddr *addr)
+{
+ return 0;
+}
#endif /* CONFIG_NETLABEL */
#endif
@@ -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 {
@@ -249,6 +249,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
sk = skb_to_full_sk(skb);
if (sk != NULL) {
struct sk_security_struct *sksec = sk->sk_security;
+
if (sksec->nlbl_state != NLBL_REQSKB)
return 0;
secattr = selinux_netlbl_sock_getattr(sk, sid);
@@ -269,6 +270,61 @@ 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
@@ -318,6 +374,22 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
sksec->nlbl_state = NLBL_UNSET;
}
+/**
+ * selinux_netlbl_sctp_sk_clone - Copy state to the newly created sock
+ * @sk: current sock
+ * @newsk: the new sock
+ *
+ * Description:
+ * Called whenever a new socket is created by accept(2) or sctp_peeloff(3).
+ */
+void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *newsksec = newsk->sk_security;
+
+ newsksec->nlbl_state = sksec->nlbl_state;
+}
+
/**
* selinux_netlbl_socket_post_create - Label a socket using NetLabel
* @sock: the socket to label
@@ -469,7 +541,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
}
/**
- * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * selinux_netlbl_socket_connect_helper - Help label a client-side socket on
+ * connect
* @sk: the socket to label
* @addr: the destination address
*
@@ -478,18 +551,13 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
* Returns zero values on success, negative values on failure.
*
*/
-int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+static int selinux_netlbl_socket_connect_helper(struct sock *sk,
+ struct sockaddr *addr)
{
int rc;
struct sk_security_struct *sksec = sk->sk_security;
struct netlbl_lsm_secattr *secattr;
- if (sksec->nlbl_state != NLBL_REQSKB &&
- sksec->nlbl_state != NLBL_CONNLABELED)
- return 0;
-
- lock_sock(sk);
-
/* connected sockets are allowed to disconnect when the address family
* is set to AF_UNSPEC, if that is what is happening we want to reset
* the socket */
@@ -497,18 +565,61 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
netlbl_sock_delattr(sk);
sksec->nlbl_state = NLBL_REQSKB;
rc = 0;
- goto socket_connect_return;
+ return rc;
}
secattr = selinux_netlbl_sock_genattr(sk);
if (secattr == NULL) {
rc = -ENOMEM;
- goto socket_connect_return;
+ return rc;
}
rc = netlbl_conn_setattr(sk, addr, secattr);
if (rc == 0)
sksec->nlbl_state = NLBL_CONNLABELED;
-socket_connect_return:
+ return rc;
+}
+
+/**
+ * selinux_netlbl_socket_connect_locked - Label a client-side socket on
+ * connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket that already has the socket locked
+ * with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect_locked(struct sock *sk,
+ struct sockaddr *addr)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+
+ if (sksec->nlbl_state != NLBL_REQSKB &&
+ sksec->nlbl_state != NLBL_CONNLABELED)
+ return 0;
+
+ return selinux_netlbl_socket_connect_helper(sk, addr);
+}
+
+/**
+ * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+ int rc;
+
+ lock_sock(sk);
+ rc = selinux_netlbl_socket_connect_locked(sk, addr);
release_sock(sk);
+
return rc;
}
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 | 157 ++++++++++++++++++ security/selinux/hooks.c | 280 +++++++++++++++++++++++++++++--- security/selinux/include/classmap.h | 2 +- security/selinux/include/netlabel.h | 21 ++- security/selinux/include/objsec.h | 4 + security/selinux/netlabel.c | 133 +++++++++++++-- 6 files changed, 565 insertions(+), 32 deletions(-) create mode 100644 Documentation/security/SELinux-sctp.rst