On Sat, Dec 30, 2017 at 05:20:13PM +0000, Richard Haines wrote:
> Add security hooks to allow security modules to exercise access control
> over SCTP.
>
> Signed-off-by: Richard Haines <richard_c_haines@xxxxxxxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> ---
> 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 | 61 +++++++++++++++++++++++++++++++++++++++++++++-
> 5 files changed, 101 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index 9942ed5..2ca0a3f 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -1271,6 +1271,16 @@ 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 cfe9712..cafac36 100644
> --- a/include/uapi/linux/sctp.h
> +++ b/include/uapi/linux/sctp.h
> @@ -123,6 +123,7 @@ typedef __s32 sctp_assoc_t;
> #define SCTP_RESET_ASSOC 120
> #define SCTP_ADD_STREAMS 121
> #define SCTP_SOCKOPT_PEELOFF_FLAGS 122
> +#define SCTP_SENDMSG_CONNECT 123
>
> /* 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 514465b..269fd3d 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -3054,6 +3054,12 @@ 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
> @@ -3120,6 +3126,12 @@ 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 8f8ccde..a2dfc5a 100644
> --- a/net/sctp/sm_statefuns.c
> +++ b/net/sctp/sm_statefuns.c
> @@ -318,6 +318,11 @@ 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.
> @@ -905,6 +910,9 @@ 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
> @@ -1433,6 +1441,11 @@ 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.
> @@ -2103,6 +2116,11 @@ 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 4373e2a..b40db2d 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -1045,6 +1045,12 @@ 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;
> @@ -1254,6 +1260,7 @@ 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.
> @@ -1367,9 +1374,17 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
> if (__copy_from_user(kaddrs, addrs, addrs_size)) {
> err = -EFAULT;
> } else {
> + /* 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:
> kfree(kaddrs);
>
> return err;
> @@ -1636,6 +1651,7 @@ 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;
> @@ -1865,6 +1881,24 @@ 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;
> @@ -2904,6 +2938,8 @@ 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;
> @@ -2911,6 +2947,17 @@ 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;
> @@ -3233,6 +3280,13 @@ 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);
> @@ -8084,6 +8138,8 @@ 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;
> @@ -8126,7 +8182,10 @@ 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,
> --
> 2.14.3
>
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