1 files changed, 37 insertions, 0 deletions

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b1f6fb36c699..bfe122764c98 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2682,4 +2682,41 @@ u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
 
         return peer_sid;
 }
+
+/**
+ * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
+ * @sock: the socket
+ * @level: the socket level or protocol
+ * @optname: the socket option name
+ *
+ * Description:
+ * Check the setsockopt() call and if the user is trying to replace the IP
+ * options on a socket and a NetLabel is in place for the socket deny the
+ * access; otherwise allow the access.  Returns zero when the access is
+ * allowed, -EACCES when denied, and other negative values on error.
+ *
+ */
+int selinux_netlbl_socket_setsockopt(struct socket *sock,
+                                     int level,
+                                     int optname)
+{
+        int rc = 0;
+        struct inode *inode = SOCK_INODE(sock);
+        struct sk_security_struct *sksec = sock->sk->sk_security;
+        struct inode_security_struct *isec = inode->i_security;
+        struct netlbl_lsm_secattr secattr;
+
+        mutex_lock(&isec->lock);
+        if (level == IPPROTO_IP && optname == IP_OPTIONS &&
+            sksec->nlbl_state == NLBL_LABELED) {
+                netlbl_secattr_init(&secattr);
+                rc = netlbl_socket_getattr(sock, &secattr);
+                if (rc == 0 && (secattr.cache || secattr.mls_lvl_vld))
+                        rc = -EACCES;
+                netlbl_secattr_destroy(&secattr);
+        }
+        mutex_unlock(&isec->lock);
+
+        return rc;
+}
 #endif /* CONFIG_NETLABEL */