From 2277c7cd75e39783eeb7512a6c35f8b4abbe1039 Mon Sep 17 00:00:00 2001 From: Richard Haines Date: Tue, 13 Feb 2018 20:56:24 +0000 Subject: [PATCH] sctp: Add LSM hooks Add security hooks allowing security modules to exercise access control over SCTP. Signed-off-by: Richard Haines Signed-off-by: Paul Moore --- include/net/sctp/structs.h | 10 ++++++ include/uapi/linux/sctp.h | 1 + net/sctp/sm_make_chunk.c | 12 ++++++++ net/sctp/sm_statefuns.c | 18 +++++++++++ net/sctp/socket.c | 62 +++++++++++++++++++++++++++++++++++++- 5 files changed, 102 insertions(+), 1 deletion(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index ead5fcedc283..7a23896cddc4 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1318,6 +1318,16 @@ struct sctp_endpoint { reconf_enable:1; __u8 strreset_enable; + + /* Security identifiers from incoming (INIT). These are set by + * security_sctp_assoc_request(). These will only be used by + * SCTP TCP type sockets and peeled off connections as they + * cause a new socket to be generated. security_sctp_sk_clone() + * will then plug these into the new socket. + */ + + u32 secid; + u32 peer_secid; }; /* Recover the outter endpoint structure. */ diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h index 4c4db14786bd..64736edd6726 100644 --- a/include/uapi/linux/sctp.h +++ b/include/uapi/linux/sctp.h @@ -126,6 +126,7 @@ typedef __s32 sctp_assoc_t; #define SCTP_STREAM_SCHEDULER 123 #define SCTP_STREAM_SCHEDULER_VALUE 124 #define SCTP_INTERLEAVING_SUPPORTED 125 +#define SCTP_SENDMSG_CONNECT 126 /* PR-SCTP policies */ #define SCTP_PR_SCTP_NONE 0x0000 diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index d01475f5f710..70274ae5ac6f 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -3071,6 +3071,12 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc, if (af->is_any(&addr)) memcpy(&addr, &asconf->source, sizeof(addr)); + if (security_sctp_bind_connect(asoc->ep->base.sk, + SCTP_PARAM_ADD_IP, + (struct sockaddr *)&addr, + af->sockaddr_len)) + return SCTP_ERROR_REQ_REFUSED; + /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address * request and does not have the local resources to add this * new address to the association, it MUST return an Error @@ -3137,6 +3143,12 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc, if (af->is_any(&addr)) memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); + if (security_sctp_bind_connect(asoc->ep->base.sk, + SCTP_PARAM_SET_PRIMARY, + (struct sockaddr *)&addr, + af->sockaddr_len)) + return SCTP_ERROR_REQ_REFUSED; + peer = sctp_assoc_lookup_paddr(asoc, &addr); if (!peer) return SCTP_ERROR_DNS_FAILED; diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index eb7905ffe5f2..42659ab68c38 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -321,6 +321,11 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net, struct sctp_packet *packet; int len; + /* Update socket peer label if first association. */ + if (security_sctp_assoc_request((struct sctp_endpoint *)ep, + chunk->skb)) + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* 6.10 Bundling * An endpoint MUST NOT bundle INIT, INIT ACK or * SHUTDOWN COMPLETE with any other chunks. @@ -908,6 +913,9 @@ enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net, */ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); + /* Set peer label for connection. */ + security_inet_conn_established(ep->base.sk, chunk->skb); + /* RFC 2960 5.1 Normal Establishment of an Association * * E) Upon reception of the COOKIE ACK, endpoint "A" will move @@ -1436,6 +1444,11 @@ static enum sctp_disposition sctp_sf_do_unexpected_init( struct sctp_packet *packet; int len; + /* Update socket peer label if first association. */ + if (security_sctp_assoc_request((struct sctp_endpoint *)ep, + chunk->skb)) + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* 6.10 Bundling * An endpoint MUST NOT bundle INIT, INIT ACK or * SHUTDOWN COMPLETE with any other chunks. @@ -2106,6 +2119,11 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook( } } + /* Update socket peer label if first association. */ + if (security_sctp_assoc_request((struct sctp_endpoint *)ep, + chunk->skb)) + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* Set temp so that it won't be added into hashtable */ new_asoc->temp = 1; diff --git a/net/sctp/socket.c b/net/sctp/socket.c index eb55c63d1990..73b34a6b5b09 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1043,6 +1043,12 @@ static int sctp_setsockopt_bindx(struct sock *sk, /* Do the work. */ switch (op) { case SCTP_BINDX_ADD_ADDR: + /* Allow security module to validate bindx addresses. */ + err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD, + (struct sockaddr *)kaddrs, + addrs_size); + if (err) + goto out; err = sctp_bindx_add(sk, kaddrs, addrcnt); if (err) goto out; @@ -1252,6 +1258,7 @@ static int __sctp_connect(struct sock *sk, if (assoc_id) *assoc_id = asoc->assoc_id; + err = sctp_wait_for_connect(asoc, &timeo); /* Note: the asoc may be freed after the return of * sctp_wait_for_connect. @@ -1347,7 +1354,16 @@ static int __sctp_setsockopt_connectx(struct sock *sk, if (unlikely(IS_ERR(kaddrs))) return PTR_ERR(kaddrs); + /* Allow security module to validate connectx addresses. */ + err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_CONNECTX, + (struct sockaddr *)kaddrs, + addrs_size); + if (err) + goto out_free; + err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id); + +out_free: kvfree(kaddrs); return err; @@ -1615,6 +1631,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) struct sctp_transport *transport, *chunk_tp; struct sctp_chunk *chunk; union sctp_addr to; + struct sctp_af *af; struct sockaddr *msg_name = NULL; struct sctp_sndrcvinfo default_sinfo; struct sctp_sndrcvinfo *sinfo; @@ -1844,6 +1861,24 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) } scope = sctp_scope(&to); + + /* Label connection socket for first association 1-to-many + * style for client sequence socket()->sendmsg(). This + * needs to be done before sctp_assoc_add_peer() as that will + * set up the initial packet that needs to account for any + * security ip options (CIPSO/CALIPSO) added to the packet. + */ + af = sctp_get_af_specific(to.sa.sa_family); + if (!af) { + err = -EINVAL; + goto out_unlock; + } + err = security_sctp_bind_connect(sk, SCTP_SENDMSG_CONNECT, + (struct sockaddr *)&to, + af->sockaddr_len); + if (err < 0) + goto out_unlock; + new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL); if (!new_asoc) { err = -ENOMEM; @@ -2909,6 +2944,8 @@ static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval, { struct sctp_prim prim; struct sctp_transport *trans; + struct sctp_af *af; + int err; if (optlen != sizeof(struct sctp_prim)) return -EINVAL; @@ -2916,6 +2953,17 @@ static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval, if (copy_from_user(&prim, optval, sizeof(struct sctp_prim))) return -EFAULT; + /* Allow security module to validate address but need address len. */ + af = sctp_get_af_specific(prim.ssp_addr.ss_family); + if (!af) + return -EINVAL; + + err = security_sctp_bind_connect(sk, SCTP_PRIMARY_ADDR, + (struct sockaddr *)&prim.ssp_addr, + af->sockaddr_len); + if (err) + return err; + trans = sctp_addr_id2transport(sk, &prim.ssp_addr, prim.ssp_assoc_id); if (!trans) return -EINVAL; @@ -3247,6 +3295,13 @@ static int sctp_setsockopt_peer_primary_addr(struct sock *sk, char __user *optva if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim.sspp_addr)) return -EADDRNOTAVAIL; + /* Allow security module to validate address. */ + err = security_sctp_bind_connect(sk, SCTP_SET_PEER_PRIMARY_ADDR, + (struct sockaddr *)&prim.sspp_addr, + af->sockaddr_len); + if (err) + return err; + /* Create an ASCONF chunk with SET_PRIMARY parameter */ chunk = sctp_make_asconf_set_prim(asoc, (union sctp_addr *)&prim.sspp_addr); @@ -8346,6 +8401,8 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk, { struct inet_sock *inet = inet_sk(sk); struct inet_sock *newinet; + struct sctp_sock *sp = sctp_sk(sk); + struct sctp_endpoint *ep = sp->ep; newsk->sk_type = sk->sk_type; newsk->sk_bound_dev_if = sk->sk_bound_dev_if; @@ -8388,7 +8445,10 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk, if (newsk->sk_flags & SK_FLAGS_TIMESTAMP) net_enable_timestamp(); - security_sk_clone(sk, newsk); + /* Set newsk security attributes from orginal sk and connection + * security attribute from ep. + */ + security_sctp_sk_clone(ep, sk, newsk); } static inline void sctp_copy_descendant(struct sock *sk_to, -- 2.30.2