From c081d53f97a1a90a38e4296dd3d6fda5e38dca2c Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 2 Nov 2021 08:02:47 -0400 Subject: [PATCH 1/4] security: pass asoc to sctp_assoc_request and sctp_sk_clone This patch is to move secid and peer_secid from endpoint to association, and pass asoc to sctp_assoc_request and sctp_sk_clone instead of ep. As ep is the local endpoint and asoc represents a connection, and in SCTP one sk/ep could have multiple asoc/connection, saving secid/peer_secid for new asoc will overwrite the old asoc's. Note that since asoc can be passed as NULL, security_sctp_assoc_request() is moved to the place right after the new_asoc is created in sctp_sf_do_5_1B_init() and sctp_sf_do_unexpected_init(). v1->v2: - fix the description of selinux_netlbl_skbuff_setsid(), as Jakub noticed. - fix the annotation in selinux_sctp_assoc_request(), as Richard Noticed. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad Reviewed-by: Richard Haines Tested-by: Richard Haines Signed-off-by: Xin Long Signed-off-by: David S. Miller --- Documentation/security/SCTP.rst | 28 ++++++++++++++-------------- include/linux/lsm_hook_defs.h | 4 ++-- include/linux/lsm_hooks.h | 8 ++++---- include/linux/security.h | 10 +++++----- include/net/sctp/structs.h | 20 ++++++++++---------- net/sctp/sm_statefuns.c | 26 +++++++++++++------------- net/sctp/socket.c | 5 ++--- security/security.c | 8 ++++---- security/selinux/hooks.c | 22 +++++++++++----------- security/selinux/include/netlabel.h | 4 ++-- security/selinux/netlabel.c | 18 +++++++++--------- 11 files changed, 76 insertions(+), 77 deletions(-) diff --git a/Documentation/security/SCTP.rst b/Documentation/security/SCTP.rst index 0bcf6c1245ee..415b548d9ce0 100644 --- a/Documentation/security/SCTP.rst +++ b/Documentation/security/SCTP.rst @@ -26,11 +26,11 @@ described in the `SCTP SELinux Support`_ chapter. security_sctp_assoc_request() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the +Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the security module. Returns 0 on success, error on failure. :: - @ep - pointer to sctp endpoint structure. + @asoc - pointer to sctp association structure. @skb - pointer to skbuff of association packet. @@ -117,9 +117,9 @@ Called whenever a new socket is created by **accept**\(2) calls **sctp_peeloff**\(3). :: - @ep - pointer to current sctp endpoint structure. + @asoc - pointer to current sctp association structure. @sk - pointer to current sock structure. - @sk - pointer to new sock structure. + @newsk - pointer to new sock structure. security_inet_conn_established() @@ -200,22 +200,22 @@ hooks with the SELinux specifics expanded below:: security_sctp_assoc_request() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Passes the ``@ep`` and ``@chunk->skb`` of the association INIT packet to the +Passes the ``@asoc`` and ``@chunk->skb`` of the association INIT packet to the security module. Returns 0 on success, error on failure. :: - @ep - pointer to sctp endpoint structure. + @asoc - pointer to sctp association structure. @skb - pointer to skbuff of association packet. The security module performs the following operations: - IF this is the first association on ``@ep->base.sk``, then set the peer + IF this is the first association on ``@asoc->base.sk``, then set the peer sid to that in ``@skb``. This will ensure there is only one peer sid - assigned to ``@ep->base.sk`` that may support multiple associations. + assigned to ``@asoc->base.sk`` that may support multiple associations. - ELSE validate the ``@ep->base.sk peer_sid`` against the ``@skb peer sid`` + ELSE validate the ``@asoc->base.sk peer_sid`` against the ``@skb peer sid`` to determine whether the association should be allowed or denied. - Set the sctp ``@ep sid`` to socket's sid (from ``ep->base.sk``) with + Set the sctp ``@asoc sid`` to socket's sid (from ``asoc->base.sk``) with MLS portion taken from ``@skb peer sid``. This will be used by SCTP TCP style sockets and peeled off connections as they cause a new socket to be generated. @@ -259,13 +259,13 @@ security_sctp_sk_clone() Called whenever a new socket is created by **accept**\(2) (i.e. a TCP style socket) or when a socket is 'peeled off' e.g userspace calls **sctp_peeloff**\(3). ``security_sctp_sk_clone()`` will set the new -sockets sid and peer sid to that contained in the ``@ep sid`` and -``@ep peer sid`` respectively. +sockets sid and peer sid to that contained in the ``@asoc sid`` and +``@asoc peer sid`` respectively. :: - @ep - pointer to current sctp endpoint structure. + @asoc - pointer to current sctp association structure. @sk - pointer to current sock structure. - @sk - pointer to new sock structure. + @newsk - pointer to new sock structure. security_inet_conn_established() diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index a9ac70ae01ab..df8de62f4710 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -329,11 +329,11 @@ LSM_HOOK(int, 0, tun_dev_create, void) LSM_HOOK(int, 0, tun_dev_attach_queue, void *security) LSM_HOOK(int, 0, tun_dev_attach, struct sock *sk, void *security) LSM_HOOK(int, 0, tun_dev_open, void *security) -LSM_HOOK(int, 0, sctp_assoc_request, struct sctp_endpoint *ep, +LSM_HOOK(int, 0, sctp_assoc_request, struct sctp_association *asoc, struct sk_buff *skb) LSM_HOOK(int, 0, sctp_bind_connect, struct sock *sk, int optname, struct sockaddr *address, int addrlen) -LSM_HOOK(void, LSM_RET_VOID, sctp_sk_clone, struct sctp_endpoint *ep, +LSM_HOOK(void, LSM_RET_VOID, sctp_sk_clone, struct sctp_association *asoc, struct sock *sk, struct sock *newsk) #endif /* CONFIG_SECURITY_NETWORK */ diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 0bada4df23fc..d45b6f6e27fd 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1027,9 +1027,9 @@ * Security hooks for SCTP * * @sctp_assoc_request: - * Passes the @ep and @chunk->skb of the association INIT packet to + * Passes the @asoc and @chunk->skb of the association INIT packet to * the security module. - * @ep pointer to sctp endpoint structure. + * @asoc pointer to sctp association structure. * @skb pointer to skbuff of association packet. * Return 0 on success, error on failure. * @sctp_bind_connect: @@ -1047,9 +1047,9 @@ * Called whenever a new socket is created by accept(2) (i.e. a TCP * style socket) or when a socket is 'peeled off' e.g userspace * calls sctp_peeloff(3). - * @ep pointer to current sctp endpoint structure. + * @asoc pointer to current sctp association structure. * @sk pointer to current sock structure. - * @sk pointer to new sock structure. + * @newsk pointer to new sock structure. * * Security hooks for Infiniband * diff --git a/include/linux/security.h b/include/linux/security.h index 7e0ba63b5dde..bbf44a466832 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -179,7 +179,7 @@ struct xfrm_policy; struct xfrm_state; struct xfrm_user_sec_ctx; struct seq_file; -struct sctp_endpoint; +struct sctp_association; #ifdef CONFIG_MMU extern unsigned long mmap_min_addr; @@ -1425,10 +1425,10 @@ int security_tun_dev_create(void); int security_tun_dev_attach_queue(void *security); int security_tun_dev_attach(struct sock *sk, void *security); int security_tun_dev_open(void *security); -int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb); +int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb); int security_sctp_bind_connect(struct sock *sk, int optname, struct sockaddr *address, int addrlen); -void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk, +void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk); #else /* CONFIG_SECURITY_NETWORK */ @@ -1631,7 +1631,7 @@ static inline int security_tun_dev_open(void *security) return 0; } -static inline int security_sctp_assoc_request(struct sctp_endpoint *ep, +static inline int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { return 0; @@ -1644,7 +1644,7 @@ static inline int security_sctp_bind_connect(struct sock *sk, int optname, return 0; } -static inline void security_sctp_sk_clone(struct sctp_endpoint *ep, +static inline void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 651bba654d77..899c29c326ba 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1355,16 +1355,6 @@ 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. */ @@ -2104,6 +2094,16 @@ struct sctp_association { __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; + /* 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; + struct rcu_head rcu; }; diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index fb3da4d8f4a3..3206374209bc 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -326,11 +326,6 @@ 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. @@ -415,6 +410,12 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net, if (!new_asoc) goto nomem; + /* Update socket peer label if first association. */ + if (security_sctp_assoc_request(new_asoc, chunk->skb)) { + sctp_association_free(new_asoc); + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + } + if (sctp_assoc_set_bind_addr_from_ep(new_asoc, sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) @@ -780,7 +781,6 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net, } } - /* Delay state machine commands until later. * * Re-build the bind address for the association is done in @@ -1517,11 +1517,6 @@ 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. @@ -1594,6 +1589,12 @@ static enum sctp_disposition sctp_sf_do_unexpected_init( if (!new_asoc) goto nomem; + /* Update socket peer label if first association. */ + if (security_sctp_assoc_request(new_asoc, chunk->skb)) { + sctp_association_free(new_asoc); + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + } + if (sctp_assoc_set_bind_addr_from_ep(new_asoc, sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) goto nomem; @@ -2255,8 +2256,7 @@ 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)) { + if (security_sctp_assoc_request(new_asoc, chunk->skb)) { sctp_association_free(new_asoc); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 6b937bfd4751..33391254fa82 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9412,7 +9412,6 @@ 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; @@ -9457,9 +9456,9 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk, net_enable_timestamp(); /* Set newsk security attributes from original sk and connection - * security attribute from ep. + * security attribute from asoc. */ - security_sctp_sk_clone(ep, sk, newsk); + security_sctp_sk_clone(asoc, sk, newsk); } static inline void sctp_copy_descendant(struct sock *sk_to, diff --git a/security/security.c b/security/security.c index 95e30fadba78..c88167a414b4 100644 --- a/security/security.c +++ b/security/security.c @@ -2367,9 +2367,9 @@ int security_tun_dev_open(void *security) } EXPORT_SYMBOL(security_tun_dev_open); -int security_sctp_assoc_request(struct sctp_endpoint *ep, struct sk_buff *skb) +int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { - return call_int_hook(sctp_assoc_request, 0, ep, skb); + return call_int_hook(sctp_assoc_request, 0, asoc, skb); } EXPORT_SYMBOL(security_sctp_assoc_request); @@ -2381,10 +2381,10 @@ int security_sctp_bind_connect(struct sock *sk, int optname, } EXPORT_SYMBOL(security_sctp_bind_connect); -void security_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk, +void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { - call_void_hook(sctp_sk_clone, ep, sk, newsk); + call_void_hook(sctp_sk_clone, asoc, sk, newsk); } EXPORT_SYMBOL(security_sctp_sk_clone); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ea7b2876a5ae..62d30c0a30c2 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5339,10 +5339,10 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent) * connect(2), sctp_connectx(3) or sctp_sendmsg(3) (with no association * already present). */ -static int selinux_sctp_assoc_request(struct sctp_endpoint *ep, +static int selinux_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { - struct sk_security_struct *sksec = ep->base.sk->sk_security; + struct sk_security_struct *sksec = asoc->base.sk->sk_security; struct common_audit_data ad; struct lsm_network_audit net = {0,}; u8 peerlbl_active; @@ -5359,7 +5359,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep, /* 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, + err = selinux_skb_peerlbl_sid(skb, asoc->base.sk->sk_family, &peer_sid); if (err) return err; @@ -5383,7 +5383,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep, */ ad.type = LSM_AUDIT_DATA_NET; ad.u.net = &net; - ad.u.net->sk = ep->base.sk; + ad.u.net->sk = asoc->base.sk; err = avc_has_perm(&selinux_state, sksec->peer_sid, peer_sid, sksec->sclass, SCTP_SOCKET__ASSOCIATION, &ad); @@ -5392,7 +5392,7 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep, } /* Compute the MLS component for the connection and store - * the information in ep. This will be used by SCTP TCP type + * the information in asoc. 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. @@ -5401,11 +5401,11 @@ static int selinux_sctp_assoc_request(struct sctp_endpoint *ep, if (err) return err; - ep->secid = conn_sid; - ep->peer_secid = peer_sid; + asoc->secid = conn_sid; + asoc->peer_secid = peer_sid; /* Set any NetLabel labels including CIPSO/CALIPSO options. */ - return selinux_netlbl_sctp_assoc_request(ep, skb); + return selinux_netlbl_sctp_assoc_request(asoc, skb); } /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting @@ -5490,7 +5490,7 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname, } /* 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, +static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { struct sk_security_struct *sksec = sk->sk_security; @@ -5502,8 +5502,8 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk, if (!selinux_policycap_extsockclass()) return selinux_sk_clone_security(sk, newsk); - newsksec->sid = ep->secid; - newsksec->peer_sid = ep->peer_secid; + newsksec->sid = asoc->secid; + newsksec->peer_sid = asoc->peer_secid; newsksec->sclass = sksec->sclass; selinux_netlbl_sctp_sk_clone(sk, newsk); } diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h index 0c58f62dc6ab..4d0456d3d459 100644 --- a/security/selinux/include/netlabel.h +++ b/security/selinux/include/netlabel.h @@ -39,7 +39,7 @@ 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, +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, 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); @@ -98,7 +98,7 @@ static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, return 0; } -static inline int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep, +static inline int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { return 0; diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 29b88e81869b..1321f15799e2 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -261,30 +261,30 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, /** * selinux_netlbl_sctp_assoc_request - Label an incoming sctp association. - * @ep: incoming association endpoint. + * @asoc: incoming association. * @skb: the packet. * * Description: - * A new incoming connection is represented by @ep, ...... + * A new incoming connection is represented by @asoc, ...... * Returns zero on success, negative values on failure. * */ -int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep, +int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { int rc; struct netlbl_lsm_secattr secattr; - struct sk_security_struct *sksec = ep->base.sk->sk_security; + struct sk_security_struct *sksec = asoc->base.sk->sk_security; struct sockaddr_in addr4; struct sockaddr_in6 addr6; - if (ep->base.sk->sk_family != PF_INET && - ep->base.sk->sk_family != PF_INET6) + if (asoc->base.sk->sk_family != PF_INET && + asoc->base.sk->sk_family != PF_INET6) return 0; netlbl_secattr_init(&secattr); rc = security_netlbl_sid_to_secattr(&selinux_state, - ep->secid, &secattr); + asoc->secid, &secattr); if (rc != 0) goto assoc_request_return; @@ -294,11 +294,11 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep, if (ip_hdr(skb)->version == 4) { addr4.sin_family = AF_INET; addr4.sin_addr.s_addr = ip_hdr(skb)->saddr; - rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr4, &secattr); + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr4, &secattr); } else if (IS_ENABLED(CONFIG_IPV6) && ip_hdr(skb)->version == 6) { addr6.sin6_family = AF_INET6; addr6.sin6_addr = ipv6_hdr(skb)->saddr; - rc = netlbl_conn_setattr(ep->base.sk, (void *)&addr6, &secattr); + rc = netlbl_conn_setattr(asoc->base.sk, (void *)&addr6, &secattr); } else { rc = -EAFNOSUPPORT; } From e215dab1c49070cd75620afd801f777207a5b65c Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 2 Nov 2021 08:02:48 -0400 Subject: [PATCH 2/4] security: call security_sctp_assoc_request in sctp_sf_do_5_1D_ce The asoc created when receives the INIT chunk is a temporary one, it will be deleted after INIT_ACK chunk is replied. So for the real asoc created in sctp_sf_do_5_1D_ce() when the COOKIE_ECHO chunk is received, security_sctp_assoc_request() should also be called. v1->v2: - fix some typo and grammar errors, noticed by Ondrej. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad Reviewed-by: Richard Haines Tested-by: Richard Haines Signed-off-by: Xin Long Signed-off-by: David S. Miller --- Documentation/security/SCTP.rst | 15 +++++++++------ net/sctp/sm_statefuns.c | 5 +++++ 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/Documentation/security/SCTP.rst b/Documentation/security/SCTP.rst index 415b548d9ce0..d5fd6ccc3dcb 100644 --- a/Documentation/security/SCTP.rst +++ b/Documentation/security/SCTP.rst @@ -151,9 +151,9 @@ establishing an association. INIT ---------------------------------------------> sctp_sf_do_5_1B_init() Respond to an INIT chunk. - SCTP peer endpoint "A" is - asking for an association. Call - security_sctp_assoc_request() + SCTP peer endpoint "A" is asking + for a temporary association. + Call security_sctp_assoc_request() to set the peer label if first association. If not first association, check @@ -163,9 +163,12 @@ establishing an association. | discard the packet. | COOKIE ECHO ------------------------------------------> - | - | - | + sctp_sf_do_5_1D_ce() + Respond to an COOKIE ECHO chunk. + Confirm the cookie and create a + permanent association. + Call security_sctp_assoc_request() to + do the same as for INIT chunk Response. <------------------------------------------- COOKIE ACK | | sctp_sf_do_5_1E_ca | diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 3206374209bc..b818532c3fc2 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -781,6 +781,11 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net, } } + if (security_sctp_assoc_request(new_asoc, chunk->skb)) { + sctp_association_free(new_asoc); + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + } + /* Delay state machine commands until later. * * Re-build the bind address for the association is done in From 7c2ef0240e6abfd3cc59511339517358350a8910 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 2 Nov 2021 08:02:49 -0400 Subject: [PATCH 3/4] security: add sctp_assoc_established hook security_sctp_assoc_established() is added to replace security_inet_conn_established() called in sctp_sf_do_5_1E_ca(), so that asoc can be accessed in security subsystem and save the peer secid to asoc->peer_secid. v1->v2: - fix the return value of security_sctp_assoc_established() in security.h, found by kernel test robot and Ondrej. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad Reviewed-by: Richard Haines Tested-by: Richard Haines Signed-off-by: Xin Long Signed-off-by: David S. Miller --- Documentation/security/SCTP.rst | 22 ++++++++++------------ include/linux/lsm_hook_defs.h | 2 ++ include/linux/lsm_hooks.h | 5 +++++ include/linux/security.h | 7 +++++++ net/sctp/sm_statefuns.c | 2 +- security/security.c | 7 +++++++ 6 files changed, 32 insertions(+), 13 deletions(-) diff --git a/Documentation/security/SCTP.rst b/Documentation/security/SCTP.rst index d5fd6ccc3dcb..406cc68b8808 100644 --- a/Documentation/security/SCTP.rst +++ b/Documentation/security/SCTP.rst @@ -15,10 +15,7 @@ For security module support, three SCTP specific hooks have been implemented:: security_sctp_assoc_request() security_sctp_bind_connect() security_sctp_sk_clone() - -Also the following security hook has been utilised:: - - security_inet_conn_established() + security_sctp_assoc_established() The usage of these hooks are described below with the SELinux implementation described in the `SCTP SELinux Support`_ chapter. @@ -122,11 +119,12 @@ calls **sctp_peeloff**\(3). @newsk - pointer to new sock structure. -security_inet_conn_established() +security_sctp_assoc_established() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Called when a COOKIE ACK is received:: +Called when a COOKIE ACK is received, and the peer secid will be +saved into ``@asoc->peer_secid`` for client:: - @sk - pointer to sock structure. + @asoc - pointer to sctp association structure. @skb - pointer to skbuff of the COOKIE ACK packet. @@ -134,7 +132,7 @@ Security Hooks used for Association Establishment ------------------------------------------------- The following diagram shows the use of ``security_sctp_bind_connect()``, -``security_sctp_assoc_request()``, ``security_inet_conn_established()`` when +``security_sctp_assoc_request()``, ``security_sctp_assoc_established()`` when establishing an association. :: @@ -172,7 +170,7 @@ establishing an association. <------------------------------------------- COOKIE ACK | | sctp_sf_do_5_1E_ca | - Call security_inet_conn_established() | + Call security_sctp_assoc_established() | to set the peer label. | | | | If SCTP_SOCKET_TCP or peeled off @@ -198,7 +196,7 @@ hooks with the SELinux specifics expanded below:: security_sctp_assoc_request() security_sctp_bind_connect() security_sctp_sk_clone() - security_inet_conn_established() + security_sctp_assoc_established() security_sctp_assoc_request() @@ -271,12 +269,12 @@ sockets sid and peer sid to that contained in the ``@asoc sid`` and @newsk - pointer to new sock structure. -security_inet_conn_established() +security_sctp_assoc_established() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Called when a COOKIE ACK is received where it sets the connection's peer sid to that in ``@skb``:: - @sk - pointer to sock structure. + @asoc - pointer to sctp association structure. @skb - pointer to skbuff of the COOKIE ACK packet. diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index df8de62f4710..442a611fa0fb 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -335,6 +335,8 @@ LSM_HOOK(int, 0, sctp_bind_connect, struct sock *sk, int optname, struct sockaddr *address, int addrlen) LSM_HOOK(void, LSM_RET_VOID, sctp_sk_clone, struct sctp_association *asoc, struct sock *sk, struct sock *newsk) +LSM_HOOK(void, LSM_RET_VOID, sctp_assoc_established, struct sctp_association *asoc, + struct sk_buff *skb) #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index d45b6f6e27fd..d6823214d5c1 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1050,6 +1050,11 @@ * @asoc pointer to current sctp association structure. * @sk pointer to current sock structure. * @newsk pointer to new sock structure. + * @sctp_assoc_established: + * Passes the @asoc and @chunk->skb of the association COOKIE_ACK packet + * to the security module. + * @asoc pointer to sctp association structure. + * @skb pointer to skbuff of association packet. * * Security hooks for Infiniband * diff --git a/include/linux/security.h b/include/linux/security.h index bbf44a466832..06eac4e61a13 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1430,6 +1430,8 @@ int security_sctp_bind_connect(struct sock *sk, int optname, struct sockaddr *address, int addrlen); void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk); +void security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb); #else /* CONFIG_SECURITY_NETWORK */ static inline int security_unix_stream_connect(struct sock *sock, @@ -1649,6 +1651,11 @@ static inline void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *newsk) { } + +static inline void security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ +} #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index b818532c3fc2..5fabaa54b77d 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -946,7 +946,7 @@ 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); + security_sctp_assoc_established((struct sctp_association *)asoc, chunk->skb); /* RFC 2960 5.1 Normal Establishment of an Association * diff --git a/security/security.c b/security/security.c index c88167a414b4..779a9edea0a0 100644 --- a/security/security.c +++ b/security/security.c @@ -2388,6 +2388,13 @@ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, } EXPORT_SYMBOL(security_sctp_sk_clone); +void security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + call_void_hook(sctp_assoc_established, asoc, skb); +} +EXPORT_SYMBOL(security_sctp_assoc_established); + #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND From e7310c94024cdf099c0d29e6903dd6fe9205bb60 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 2 Nov 2021 08:02:50 -0400 Subject: [PATCH 4/4] security: implement sctp_assoc_established hook in selinux Different from selinux_inet_conn_established(), it also gives the secid to asoc->peer_secid in selinux_sctp_assoc_established(), as one UDP-type socket may have more than one asocs. Note that peer_secid in asoc will save the peer secid for this asoc connection, and peer_sid in sksec will just keep the peer secid for the latest connection. So the right use should be do peeloff for UDP-type socket if there will be multiple asocs in one socket, so that the peeloff socket has the right label for its asoc. v1->v2: - call selinux_inet_conn_established() to reduce some code duplication in selinux_sctp_assoc_established(), as Ondrej suggested. - when doing peeloff, it calls sock_create() where it actually gets secid for socket from socket_sockcreate_sid(). So reuse SECSID_WILD to ensure the peeloff socket keeps using that secid after calling selinux_sctp_sk_clone() for client side. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad Reviewed-by: Richard Haines Tested-by: Richard Haines Signed-off-by: Xin Long Signed-off-by: David S. Miller --- security/selinux/hooks.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 62d30c0a30c2..5e5215fe2e83 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5502,7 +5502,8 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk if (!selinux_policycap_extsockclass()) return selinux_sk_clone_security(sk, newsk); - newsksec->sid = asoc->secid; + if (asoc->secid != SECSID_WILD) + newsksec->sid = asoc->secid; newsksec->peer_sid = asoc->peer_secid; newsksec->sclass = sksec->sclass; selinux_netlbl_sctp_sk_clone(sk, newsk); @@ -5558,6 +5559,16 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); } +static void selinux_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + struct sk_security_struct *sksec = asoc->base.sk->sk_security; + + selinux_inet_conn_established(asoc->base.sk, skb); + asoc->peer_secid = sksec->peer_sid; + asoc->secid = SECSID_WILD; +} + static int selinux_secmark_relabel_packet(u32 sid) { const struct task_security_struct *__tsec; @@ -7228,6 +7239,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { 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(sctp_assoc_established, selinux_sctp_assoc_established), 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),