[PATCH net 3/4] security: add sctp_assoc_established hook
Xin Long
lucien.xin at gmail.com
Fri Oct 22 06:36:11 UTC 2021
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 <pprahlad at redhat.com>
Signed-off-by: Xin Long <lucien.xin at gmail.com>
---
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 | 2 +-
security/security.c | 7 +++++++
6 files changed, 33 insertions(+), 13 deletions(-)
diff --git a/Documentation/security/SCTP.rst b/Documentation/security/SCTP.rst
index 9a38067762e5..3ebbcd80b3e7 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 0024273a7382..e9870118cc67 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -334,6 +334,8 @@ 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 240b92d89852..ba42c22204e2 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1047,6 +1047,11 @@
* @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 a16407444871..11cdddf9685c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1423,6 +1423,8 @@ 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,
@@ -1642,6 +1644,12 @@ 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)
+{
+ 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 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 b0f1c007aa3b..4b2b4b5beb27 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2387,6 +2387,13 @@ 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
--
2.27.0
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