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sctp: Add LSM hooks

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Add security hooks allowing security modules to exercise access control
over SCTP.

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Richard Haines 2018-02-13 20:56:24 +00:00 committed by Paul Moore
parent b7e10c25b8
commit 2277c7cd75
5 changed files with 102 additions and 1 deletions
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10
include/net/sctp/structs.h
View file

@ -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. */

1
include/uapi/linux/sctp.h
View file

@ -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

12
net/sctp/sm_make_chunk.c
View file

@ -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;

18
net/sctp/sm_statefuns.c
View file

@ -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;

62
net/sctp/socket.c
View file

@ -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,