From: Jan Klemkow <jan@openbsd.org>
Subject: ypldap: fix endless loop
To: tech@openbsd.org
Date: Tue, 30 Jun 2026 09:45:28 +0200

Hi,

If the connection behind ldap->fd is closed, this leads into an endless
loop and 100% CPU consumption here.  Also, an error of evbuffer_add(3)
should not ignored here.

ok?

bye,
Jan

Index: aldap.c
===================================================================
RCS file: /cvs/src/usr.sbin/ypldap/aldap.c,v
diff -u -p -r1.49 aldap.c
--- aldap.c	13 Oct 2022 04:55:33 -0000	1.49
+++ aldap.c	30 Jun 2026 07:43:40 -0000
@@ -405,11 +405,12 @@ aldap_parse(struct aldap *ldap)
 			} else
 				ret = read(ldap->fd, rbuf, sizeof(rbuf));
 
-			if (ret == -1) {
+			if (ret == -1 || ret == 0) {
 				goto parsefail;
 			}
 
-			evbuffer_add(ldap->buf, rbuf, ret);
+			if (evbuffer_add(ldap->buf, rbuf, ret) == -1)
+				goto parsefail;
 		}
 
 		if (EVBUFFER_LENGTH(ldap->buf) > 0) {