ctdb/tcp/tcp_connect.c set socket close on exec

Set SOCKET_CLOEXEC on the sockets returned by accept.  This ensures that
the socket is unavailable to any child process created by system().
Making it harder for malicious code to set up a command channel,
as seen in the exploit for CVE-2015-0240

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/ctdb/tcp/tcp_connect.c b/ctdb/tcp/tcp_connect.c
index 82f2e746192e061f237d54fe4df7d31f3e546437..17aafc415f7c80f6f8a66bcb840f7f3d290ded90 100644 (file)
--- a/ctdb/tcp/tcp_connect.c
+++ b/ctdb/tcp/tcp_connect.c
@@ -249,6 +249,7 @@ static void ctdb_listen_event(struct tevent_context *ev, struct tevent_fd *fde,
        len = sizeof(addr);
        fd = accept(ctcp->listen_fd, (struct sockaddr *)&addr, &len);
        if (fd == -1) return;
+       smb_set_close_on_exec(fd);
 
        nodeid = ctdb_ip_to_nodeid(ctdb, &addr);