libuuid: Make sure fd's 0, 1, and 2 are valid before exec'ing uuidd

When closing all of the file descriptors before starting uuidd, make
sure file descriptors 0, 1, and 2 are reserved by opening /dev/null.
This prevents strange bugs caused by assumptions regarding file
descriptors <= 2 as being special.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

shlibs/uuid/src/gen_uuid.c

@@ -461,8 +461,11 @@ static void close_all_fds(void)
 	max = OPEN_MAX;
 #endif
 
-	for (i=0; i < max; i++)
+	for (i=0; i < max; i++) {
 		close(i);
+		if (i <= 2)
+			open("/dev/null", O_RDWR);
+	}
 }
 
 /*