| Message ID | 20171127193217.2768-1-richard_c_haines@btinternet.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; > } -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; > > } -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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
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; > > > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux- > security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; }
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