libnl_2: Fix memory leaks

BUG: b/5532633

Change-Id: I271168764e26dc465d2442f5015338a3e9a479b8
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

3 files changed, 34 insertions, 27 deletions

diff --git a/libnl_2/handlers.c b/libnl_2/handlers.c
index ec8d512..48dcab4 100644
--- a/libnl_2/handlers.c
+++ b/libnl_2/handlers.c
@@ -39,16 +39,14 @@ fail:
 struct nl_cb *nl_cb_clone(struct nl_cb *orig)
 {
 	struct nl_cb *new_cb;
-	int new_refcnt;
 
 	new_cb = nl_cb_alloc(NL_CB_DEFAULT);
 	if (new_cb == NULL)
 		goto fail;
 
-	/* Preserve reference count and copy original */
-	new_refcnt = new_cb->cb_refcnt;
+	/* Copy original and set refcount to 1 */
 	memcpy(new_cb, orig, sizeof(*orig));
-	new_cb->cb_refcnt = new_refcnt;
+	new_cb->cb_refcnt = 1;
 
 	return new_cb;
 fail:
@@ -84,9 +82,9 @@ struct nl_cb *nl_cb_get(struct nl_cb *cb)
 
 void nl_cb_put(struct nl_cb *cb)
 {
+	if (!cb)
+		return;
 	cb->cb_refcnt--;
 	if (cb->cb_refcnt <= 0)
 		free(cb);
-
 }
-
diff --git a/libnl_2/netlink.c b/libnl_2/netlink.c
index cc2f88e..ee3d600 100644
--- a/libnl_2/netlink.c
+++ b/libnl_2/netlink.c
@@ -59,15 +59,14 @@ int nl_recv(struct nl_sock *sk, struct sockaddr_nl *nla, \
 {
 	int rc = -1;
 	int sk_flags;
-	int RECV_BUF_SIZE;
+	int RECV_BUF_SIZE = getpagesize();
 	int errsv;
 	struct iovec recvmsg_iov;
 	struct msghdr msg;
 
 	/* Allocate buffer */
-	RECV_BUF_SIZE = getpagesize();
 	*buf = (unsigned char *) malloc(RECV_BUF_SIZE);
-	if (!buf) {
+	if (!(*buf)) {
 		rc = -ENOMEM;
 		goto fail;
 	}
@@ -91,8 +90,11 @@ int nl_recv(struct nl_sock *sk, struct sockaddr_nl *nla, \
 	errsv = errno;
 	fcntl(sk->s_fd, F_SETFL, sk_flags);
 
-	if (rc < 0)
+	if (rc < 0) {
 		rc = -errsv;
+		free(*buf);
+		*buf = NULL;
+	}
 
 fail:
 	return rc;
@@ -108,7 +110,6 @@ int nl_recvmsgs(struct nl_sock *sk, struct nl_cb *cb)
 	int rc, cb_rc = NL_OK, done = 0;
 
 	do {
-
 		unsigned char *buf;
 		int i, rem, flags;
 		struct nlmsghdr *nlh;
@@ -127,7 +128,7 @@ int nl_recvmsgs(struct nl_sock *sk, struct nl_cb *cb)
 
 			/* Check for callbacks */
 
-			msg = (struct nl_msg *)malloc(sizeof(struct nl_msg));
+			msg = (struct nl_msg *) malloc(sizeof(struct nl_msg));
 			memset(msg, 0, sizeof(*msg));
 			msg->nm_nlh = nlh;
 
@@ -187,7 +188,6 @@ int nl_recvmsgs(struct nl_sock *sk, struct nl_cb *cb)
 			if (done)
 				break;
 		}
-
 		free(buf);
 		buf = NULL;
 
@@ -197,7 +197,7 @@ int nl_recvmsgs(struct nl_sock *sk, struct nl_cb *cb)
 
 success:
 fail:
-	return	rc;
+	return rc;
 }
 
 /* Send raw data over netlink socket */
diff --git a/libnl_2/socket.c b/libnl_2/socket.c
index ce54f19..d906cac 100644
--- a/libnl_2/socket.c
+++ b/libnl_2/socket.c
@@ -31,7 +31,7 @@ int nl_socket_add_membership(struct nl_sock *sk, int group)
 }
 
 /* Allocate new netlink socket. */
-struct nl_sock *nl_socket_alloc(void)
+static struct nl_sock *_nl_socket_alloc(void)
 {
 	struct nl_sock *sk;
 	struct timeval tv;
@@ -39,13 +39,13 @@ struct nl_sock *nl_socket_alloc(void)
 
 	sk = (struct nl_sock *) malloc(sizeof(struct nl_sock));
 	if (!sk)
-		goto fail;
+		return NULL;
 	memset(sk, 0, sizeof(*sk));
 
 	/* Get current time */
 
 	if (gettimeofday(&tv, NULL))
-		return NULL;
+		goto fail;
 	else
 		sk->s_seq_next = (int) tv.tv_sec;
 
@@ -59,24 +59,36 @@ struct nl_sock *nl_socket_alloc(void)
 	sk->s_peer.nl_pid = 0; /* Kernel */
 	sk->s_peer.nl_groups = 0; /* No groups */
 
-	cb = (struct nl_cb *) malloc(sizeof(struct nl_cb));
-	if (!cb)
-		goto cb_fail;
-	memset(cb, 0, sizeof(*cb));
-	sk->s_cb = nl_cb_alloc(NL_CB_DEFAULT);
+	return sk;
+fail:
+	free(sk);
+	return NULL;
+}
 
+/* Allocate new netlink socket. */
+struct nl_sock *nl_socket_alloc(void)
+{
+	struct nl_sock *sk = _nl_socket_alloc();
+	struct nl_cb *cb;
 
+	if (!sk)
+		return NULL;
+
+	cb = nl_cb_alloc(NL_CB_DEFAULT);
+	if (!cb)
+		goto cb_fail;
+	sk->s_cb = cb;
 	return sk;
 cb_fail:
 	free(sk);
-fail:
 	return NULL;
 }
 
 /* Allocate new socket with custom callbacks. */
 struct nl_sock *nl_socket_alloc_cb(struct nl_cb *cb)
 {
-	struct nl_sock *sk = nl_socket_alloc();
+	struct nl_sock *sk = _nl_socket_alloc();
+
 	if (!sk)
 		return NULL;
 
@@ -84,7 +96,6 @@ struct nl_sock *nl_socket_alloc_cb(struct nl_cb *cb)
 	nl_cb_get(cb);
 
 	return sk;
-
 }
 
 /* Free a netlink socket. */
@@ -116,5 +127,3 @@ int nl_socket_get_fd(struct nl_sock *sk)
 {
 	return sk->s_fd;
 }
-
-