diff --git a/libssh/agent.c b/libssh/agent.c
index 3a8c56ee..8a938907 100644
--- a/libssh/agent.c
+++ b/libssh/agent.c
@@ -124,6 +124,9 @@ AGENT *agent_new(struct ssh_session *session) {
   if (agent) {
     agent->count = 0;
     agent->sock = ssh_socket_new(session);
+    if (agent->sock == NULL) {
+      return NULL;
+    }
   }
 
   return agent;
diff --git a/libssh/session.c b/libssh/session.c
index 0feaabc5..1ba30d8d 100644
--- a/libssh/session.c
+++ b/libssh/session.c
@@ -52,9 +52,16 @@ SSH_SESSION *ssh_new(void) {
     session->out_buffer=buffer_new();
     session->in_buffer=buffer_new();
 #ifndef _WIN32
-    session->agent=agent_new(session);
+    session->agent = agent_new(session);
+    if (session->agent == NULL) {
+      goto err;
+    }
 #endif /* _WIN32 */
     return session;
+
+err:
+    ssh_cleanup(session);
+    return NULL;
 }
 
 void ssh_cleanup(SSH_SESSION *session){
diff --git a/libssh/socket.c b/libssh/socket.c
index acadbeda..03797d61 100644
--- a/libssh/socket.c
+++ b/libssh/socket.c
@@ -89,7 +89,12 @@ void ssh_socket_init(void) {
  * \brief creates a new Socket object
  */
 struct socket *ssh_socket_new(SSH_SESSION *session){
-	struct socket *s=malloc(sizeof(struct socket));
+	struct socket *s;
+
+        s = malloc(sizeof(struct socket));
+        if (s = NULL) {
+          return NULL;
+        }
 	s->fd=-1;
 	s->last_errno=-1;
 	s->session=session;
@@ -351,6 +356,10 @@ int ssh_socket_wait_for_data(struct socket *s, SSH_SESSION *session, u32 len){
     }
     if(session->blocking){
         buf=malloc(to_read);
+        if (buf == NULL) {
+          leave_function();
+          return SSH_ERROR;
+        }
         r=ssh_socket_completeread(session->socket,buf,to_read);
         if(r==SSH_ERROR || r ==0){
             ssh_set_error(session,SSH_FATAL,