[NetLabel]: correct improper handling of non-NetLabel peer contexts

Fix a problem where NetLabel would always set the value of 
sk_security_struct->peer_sid in selinux_netlbl_sock_graft() to the context of
the socket, causing problems when users would query the context of the
connection.  This patch fixes this so that the value in
sk_security_struct->peer_sid is only set when the connection is NetLabel based,
otherwise the value is untouched.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 56 insertions, 15 deletions

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 80a2a0911b49..a3bae2ca8acc 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1486,43 +1486,40 @@ socket_setattr_failure:
 }
 
 /**
- * cipso_v4_socket_getattr - Get the security attributes from a socket
- * @sock: the socket
+ * cipso_v4_sock_getattr - Get the security attributes from a sock
+ * @sk: the sock
  * @secattr: the security attributes
  *
  * Description:
- * Query @sock to see if there is a CIPSO option attached to the socket and if
- * there is return the CIPSO security attributes in @secattr.  Returns zero on
- * success and negative values on failure.
+ * Query @sk to see if there is a CIPSO option attached to the sock and if
+ * there is return the CIPSO security attributes in @secattr.  This function
+ * requires that @sk be locked, or privately held, but it does not do any
+ * locking itself.  Returns zero on success and negative values on failure.
  *
  */
-int cipso_v4_socket_getattr(const struct socket *sock,
-                            struct netlbl_lsm_secattr *secattr)
+int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
 {
         int ret_val = -ENOMSG;
-        struct sock *sk;
         struct inet_sock *sk_inet;
         unsigned char *cipso_ptr;
         u32 doi;
         struct cipso_v4_doi *doi_def;
 
-        sk = sock->sk;
-        lock_sock(sk);
         sk_inet = inet_sk(sk);
         if (sk_inet->opt == NULL || sk_inet->opt->cipso == 0)
-                goto socket_getattr_return;
+                return -ENOMSG;
         cipso_ptr = sk_inet->opt->__data + sk_inet->opt->cipso -
                 sizeof(struct iphdr);
         ret_val = cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr);
         if (ret_val == 0)
-                goto socket_getattr_return;
+                return ret_val;
 
         doi = ntohl(*(u32 *)&cipso_ptr[2]);
         rcu_read_lock();
         doi_def = cipso_v4_doi_getdef(doi);
         if (doi_def == NULL) {
                 rcu_read_unlock();
-                goto socket_getattr_return;
+                return -ENOMSG;
         }
         switch (cipso_ptr[6]) {
         case CIPSO_V4_TAG_RBITMAP:
@@ -1533,8 +1530,29 @@ int cipso_v4_socket_getattr(const struct socket *sock,
         }
         rcu_read_unlock();
 
-socket_getattr_return:
-        release_sock(sk);
+        return ret_val;
+}
+
+/**
+ * cipso_v4_socket_getattr - Get the security attributes from a socket
+ * @sock: the socket
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Query @sock to see if there is a CIPSO option attached to the socket and if
+ * there is return the CIPSO security attributes in @secattr.  Returns zero on
+ * success and negative values on failure.
+ *
+ */
+int cipso_v4_socket_getattr(const struct socket *sock,
+                            struct netlbl_lsm_secattr *secattr)
+{
+        int ret_val;
+
+        lock_sock(sock->sk);
+        ret_val = cipso_v4_sock_getattr(sock->sk, secattr);
+        release_sock(sock->sk);
+
         return ret_val;
 }
 
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index 0fd8aaafe23f..54fb7de3c2b1 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -85,6 +85,29 @@ socket_setattr_return:
 }
 
 /**
+ * netlbl_sock_getattr - Determine the security attributes of a sock
+ * @sk: the sock
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Examines the given sock to see any NetLabel style labeling has been
+ * applied to the sock, if so it parses the socket label and returns the
+ * security attributes in @secattr.  Returns zero on success, negative values
+ * on failure.
+ *
+ */
+int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
+{
+        int ret_val;
+
+        ret_val = cipso_v4_sock_getattr(sk, secattr);
+        if (ret_val == 0)
+                return 0;
+
+        return netlbl_unlabel_getattr(secattr);
+}
+
+/**
  * netlbl_socket_getattr - Determine the security attributes of a socket
  * @sock: the socket
  * @secattr: the security attributes