diff -up sudo-1.8.6p7/src/ttyname.c.get_process_ttyname sudo-1.8.6p7/src/ttyname.c
--- sudo-1.8.6p7/src/ttyname.c.get_process_ttyname	2013-02-25 20:46:09.000000000 +0100
+++ sudo-1.8.6p7/src/ttyname.c	2017-05-25 10:23:28.720850944 +0200
@@ -171,6 +171,8 @@ static char *search_devs[] = {
 
 static char *ignore_devs[] = {
     "/dev/fd/",
+    "/dev/mqueue/",
+    "/dev/shm/",
     "/dev/stdin",
     "/dev/stdout",
     "/dev/stderr",
@@ -437,9 +439,13 @@ get_process_ttyname(void)
 	len = getline(&line, &linesize, fp);
 	fclose(fp);
 	if (len != -1) {
-	    /* Field 7 is the tty dev (0 if no tty) */
-	    char *cp = line;
-	    int field = 1;
+	    /*
+	     * Field 7 is the tty dev (0 if no tty).
+	     * Since the process name at field 2 "(comm)" may include spaces,
+	     * start at the last ')' found.
+	     */
+	    char *cp = strrchr(line, ')');
+	    int field = 2;
 	    while (*cp != '\0') {
 		if (*cp++ == ' ') {
 		    if (++field == 7) {