3 files changed, 54 insertions, 1 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e9969a2fc846..8ab5679a37a3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3313,7 +3313,13 @@ static int selinux_socket_getpeername(struct socket *sock)
 
 static int selinux_socket_setsockopt(struct socket *sock,int level,int optname)
 {
-        return socket_has_perm(current, sock, SOCKET__SETOPT);
+        int err;
+
+        err = socket_has_perm(current, sock, SOCKET__SETOPT);
+        if (err)
+                return err;
+
+        return selinux_netlbl_socket_setsockopt(sock, level, optname);
 }
 
 static int selinux_socket_getsockopt(struct socket *sock, int level,
diff --git a/security/selinux/include/selinux_netlabel.h b/security/selinux/include/selinux_netlabel.h
index ecab4bddaaf4..9de10cc2cef2 100644
--- a/security/selinux/include/selinux_netlabel.h
+++ b/security/selinux/include/selinux_netlabel.h
@@ -53,6 +53,9 @@ void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
 void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec,
                                       struct sk_security_struct *newssec);
 int selinux_netlbl_inode_permission(struct inode *inode, int mask);
+int selinux_netlbl_socket_setsockopt(struct socket *sock,
+                                     int level,
+                                     int optname);
 #else
 static inline void selinux_netlbl_cache_invalidate(void)
 {
@@ -114,6 +117,13 @@ static inline int selinux_netlbl_inode_permission(struct inode *inode,
 {
         return 0;
 }
+
+static inline int selinux_netlbl_socket_setsockopt(struct socket *sock,
+                                                   int level,
+                                                   int optname)
+{
+        return 0;
+}
 #endif /* CONFIG_NETLABEL */
 
 #endif
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 */