ext/socket/init.c (rsock_init_sock): reject reserved FDs

[ruby-core:72445] [Bug #11862]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53259 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Dec 23 07:15:17 2015  Eric Wong  <e@80x24.org>
+
+	* ext/socket/init.c (rsock_init_sock): reject reserved FDs
+	  [ruby-core:72445] [Bug #11862]
+
 Wed Dec 23 02:59:26 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (__STDC_WANT_LIB_EXT1__): necessary to use memset_s

ext/socket/init.c

@@ -61,7 +61,7 @@ rsock_init_sock(VALUE sock, int fd)
 {
     rb_io_t *fp;
 
-    if (!is_socket(fd)) {
+    if (!is_socket(fd) || rb_reserved_fd_p(fd)) {
 	errno = EBADF;
 	rb_sys_fail("not a socket file descriptor");
     }