From 5e50f5d4ff31e95599d695df1f0a4e7d2d6fef99 Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Sat, 12 Feb 2022 18:59:21 +0100 Subject: [PATCH] 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. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad Based-on-patch-by: Xin Long Reviewed-by: Xin Long Tested-by: Richard Haines Signed-off-by: Ondrej Mosnacek Signed-off-by: Paul Moore --- Documentation/security/SCTP.rst | 22 ++++++++++------------ include/linux/lsm_hook_defs.h | 2 ++ include/linux/lsm_hooks.h | 5 +++++ include/linux/security.h | 8 ++++++++ net/sctp/sm_statefuns.c | 8 +++++--- security/security.c | 7 +++++++ 6 files changed, 37 insertions(+), 15 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 a5a724c308d8..45931d81ccc3 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -332,6 +332,8 @@ 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(int, 0, 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 3bf5c658bc44..419b5febc3ca 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1046,6 +1046,11 @@ * @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 6d72772182c8..25b3ef71f495 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1422,6 +1422,8 @@ 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); +int 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, @@ -1641,6 +1643,12 @@ static inline void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *newsk) { } + +static inline int security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + return 0; +} #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index cc544a97c4af..7f342bc12735 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -930,6 +930,11 @@ enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net, if (!sctp_vtag_verify(chunk, asoc)) return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* Set peer label for connection. */ + if (security_sctp_assoc_established((struct sctp_association *)asoc, + chunk->skb)) + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* Verify that the chunk length for the COOKIE-ACK is OK. * If we don't do this, any bundled chunks may be junked. */ @@ -945,9 +950,6 @@ 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 diff --git a/security/security.c b/security/security.c index e649c8691be2..9663ffcca4b0 100644 --- a/security/security.c +++ b/security/security.c @@ -2393,6 +2393,13 @@ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, } EXPORT_SYMBOL(security_sctp_sk_clone); +int security_sctp_assoc_established(struct sctp_association *asoc, + struct sk_buff *skb) +{ + return call_int_hook(sctp_assoc_established, 0, asoc, skb); +} +EXPORT_SYMBOL(security_sctp_assoc_established); + #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND