2 files changed, 18 insertions, 1 deletions

diff --git a/source/winbindd/winbindd.c b/source/winbindd/winbindd.c
index 1d618e26317..6b5c251bf6b 100644
--- a/source/winbindd/winbindd.c
+++ b/source/winbindd/winbindd.c
@@ -836,7 +836,8 @@ static void process_loop(void)
 	listen_sock = open_winbindd_socket();
 	listen_priv_sock = open_winbindd_priv_socket();
 
-	if (listen_sock == -1 || listen_priv_sock == -1) {
+	if (listen_sock < 0 || listen_sock >= FD_SETSIZE ||
+			listen_priv_sock < 0 || listen_priv_sock >= FD_SETSIZE) {
 		perror("open_winbind_socket");
 		exit(1);
 	}
@@ -861,6 +862,9 @@ static void process_loop(void)
 
 	FD_ZERO(&r_fds);
 	FD_ZERO(&w_fds);
+
+	/* We check the range for listen_sock and
+	   listen_priv_sock above. */
 	FD_SET(listen_sock, &r_fds);
 	FD_SET(listen_priv_sock, &r_fds);
 
@@ -890,6 +894,12 @@ static void process_loop(void)
 	}
 
 	for (ev = fd_events; ev; ev = ev->next) {
+		if (ev->fd < 0 || ev->fd >= FD_SETSIZE) {
+			/* Ignore here - event_add_to_select_args
+			   should make this impossible. */
+			continue;
+		}
+
 		if (ev->flags & EVENT_FD_READ) {
 			FD_SET(ev->fd, &r_fds);
 			maxfd = MAX(ev->fd, maxfd);
diff --git a/source/winbindd/winbindd_dual.c b/source/winbindd/winbindd_dual.c
index ff004f293ce..b30ec20b4a1 100644
--- a/source/winbindd/winbindd_dual.c
+++ b/source/winbindd/winbindd_dual.c
@@ -1250,6 +1250,12 @@ static bool fork_domain_child(struct winbindd_child *child)
 		return False;
 	}
 
+	if (fdpair[0] < 0 || fdpair[0] >= FD_SETSIZE) {
+		DEBUG(0, ("fork_domain_child: bad fd range (%d)\n", fdpair[0]));
+		errno = EBADF;
+		return False;
+	}
+
 	ZERO_STRUCT(state);
 	state.pid = sys_getpid();
 
@@ -1405,6 +1411,7 @@ static bool fork_domain_child(struct winbindd_child *child)
 		message_dispatch(winbind_messaging_context());
 
 		FD_ZERO(&read_fds);
+		/* We check state.sock against FD_SETSIZE above. */
 		FD_SET(state.sock, &read_fds);
 
 		ret = sys_select(state.sock + 1, &read_fds, NULL, NULL, tp);