diff -Nru apache2-2.4.29/debian/changelog apache2-2.4.29/debian/changelog
--- apache2-2.4.29/debian/changelog	2018-02-06 11:57:20.000000000 +0000
+++ apache2-2.4.29/debian/changelog	2018-03-02 02:19:31.000000000 +0000
@@ -1,3 +1,10 @@
+apache2 (2.4.29-1ubuntu4) bionic; urgency=medium
+
+  * Avoid crashes, hangs and loops by fixing mod_ldap locking: (LP: #1752683)
+    - added debian/patches/util_ldap_cache_lock_fix.patch
+
+ -- Rafael David Tinoco <rafael.tinoco@canonical.com>  Fri, 02 Mar 2018 02:19:31 +0000
+
 apache2 (2.4.29-1ubuntu3) bionic; urgency=medium
 
   * Switch back to OpenSSL 1.1.
diff -Nru apache2-2.4.29/debian/patches/series apache2-2.4.29/debian/patches/series
--- apache2-2.4.29/debian/patches/series	2017-11-10 15:51:46.000000000 +0000
+++ apache2-2.4.29/debian/patches/series	2018-03-02 02:19:13.000000000 +0000
@@ -15,3 +15,4 @@
 # Patches added by Ubuntu
 086_svn_cross_compiles
 
+util_ldap_cache_lock_fix.patch
diff -Nru apache2-2.4.29/debian/patches/util_ldap_cache_lock_fix.patch apache2-2.4.29/debian/patches/util_ldap_cache_lock_fix.patch
--- apache2-2.4.29/debian/patches/util_ldap_cache_lock_fix.patch	1970-01-01 00:00:00.000000000 +0000
+++ apache2-2.4.29/debian/patches/util_ldap_cache_lock_fix.patch	2018-03-02 02:19:26.000000000 +0000
@@ -0,0 +1,47 @@
+Description: [PATCH] Merge r1824811 from trunk:
+
+ 00:00:00 2001 From: Yann Ylavic <ylavic@apache.org> Date: Tue, 20 Feb 2018
+ 13:02:54 +0000 Subject: [PATCH] Merge r1824811 from trunk:
+
+10 years after r567503 , fix this properly.
+
+The lock is created in post_config, so we can't copy it
+around in a merge_server_config() callback.
+
+Submitted by: covener
+Reviewed by: covener, rpluem, jim
+--
+Origin: https://bz.apache.org/bugzilla/show_bug.cgi?id=60296
+Origin: upstream, commit: 39ae6cd642689c20b599727ee1fb95233faabb05
+Bug: https://bz.apache.org/bugzilla/show_bug.cgi?id=58483
+Bug: https://bz.apache.org/bugzilla/show_bug.cgi?id=60296
+Bug-Debian: https://bugs.debian.org/814980
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/1752683
+Reviewed-by: Rafael David Tinoco <rafael.tinoco@canonical.com>
+Last-Update: 2018-03-01
+
+--- apache2-2.4.29.orig/modules/ldap/util_ldap.c
++++ apache2-2.4.29/modules/ldap/util_ldap.c
+@@ -2858,7 +2858,6 @@ static void *util_ldap_merge_config(apr_
+     st->search_cache_size = base->search_cache_size;
+     st->compare_cache_ttl = base->compare_cache_ttl;
+     st->compare_cache_size = base->compare_cache_size;
+-    st->util_ldap_cache_lock = base->util_ldap_cache_lock;
+ 
+     st->connections = NULL;
+     st->ssl_supported = 0; /* not known until post-config and re-merged */
+@@ -2977,12 +2976,12 @@ static int util_ldap_post_config(apr_poo
+             st_vhost = (util_ldap_state_t *)
+                        ap_get_module_config(s_vhost->module_config,
+                                             &ldap_module);
+-
++            st_vhost->util_ldap_cache = st->util_ldap_cache;
++            st_vhost->util_ldap_cache_lock = st->util_ldap_cache_lock;
+ #if APR_HAS_SHARED_MEMORY
+             st_vhost->cache_shm = st->cache_shm;
+             st_vhost->cache_rmm = st->cache_rmm;
+             st_vhost->cache_file = st->cache_file;
+-            st_vhost->util_ldap_cache = st->util_ldap_cache;
+             ap_log_error(APLOG_MARK, APLOG_DEBUG, result, s, APLOGNO(01316)
+                          "LDAP merging Shared Cache conf: shm=0x%pp rmm=0x%pp "
+                          "for VHOST: %s", st->cache_shm, st->cache_rmm,