From b01e30c79b1364ac35c0b2db2ef4a2ff64600a7f Mon Sep 17 00:00:00 2001
From: tbordaz <tbordaz@redhat.com>
Date: Tue, 23 Feb 2021 08:58:37 +0100
Subject: [PATCH 1/2] Issue 4649 - crash in sync_repl when a MODRDN create a
 cenotaph (#4652)

Bug description:
	When an operation is flagged OP_FLAG_NOOP, it skips BETXN plugins but calls POST plugins.
	For sync_repl, betxn (sync_update_persist_betxn_pre_op) creates an operation extension to be
	consumed by the post (sync_update_persist_op). In case of OP_FLAG_NOOP, there is no
	operation extension.

Fix description:
	Test that the operation is OP_FLAG_NOOP if the operation extension is missing

relates: https://github.com/389ds/389-ds-base/issues/4649

Reviewed by: William Brown (thanks)

Platforms tested: F31
---
 ldap/servers/plugins/sync/sync_persist.c      | 14 ++++-
 2 files changed, 75 insertions(+), 2 deletions(-)
diff --git a/ldap/servers/plugins/sync/sync_persist.c b/ldap/servers/plugins/sync/sync_persist.c
index e93a8fa83..12b23ebac 100644
--- a/ldap/servers/plugins/sync/sync_persist.c
+++ b/ldap/servers/plugins/sync/sync_persist.c
@@ -206,7 +206,9 @@ sync_update_persist_op(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *eprev, ber
     slapi_pblock_get(pb, SLAPI_TARGET_SDN, &sdn);
 
     if (NULL == e) {
-        /* Ignore this operation (for example case of failure of the operation) */
+        /* Ignore this operation (for example case of failure of the operation
+         * or operation resulting in an empty Mods))
+         */
         ignore_op_pl(pb);
         return;
     }
@@ -232,7 +234,15 @@ sync_update_persist_op(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *eprev, ber
     prim_op = get_thread_primary_op();
     ident = sync_persist_get_operation_extension(pb);
     PR_ASSERT(prim_op);
-    PR_ASSERT(ident);
+
+    if ((ident == NULL) && operation_is_flag_set(pb_op, OP_FLAG_NOOP)) {
+        /* This happens for URP (add cenotaph, fixup rename, tombstone resurrect)
+         * As a NOOP betxn plugins are not called and operation ext is not created
+         */
+        slapi_log_err(SLAPI_LOG_PLUGIN, SYNC_PLUGIN_SUBSYSTEM, "Skip noop operation (0x%lx)\n",
+                       (ulong) pb_op);
+        return;
+    }
     /* First mark the operation as completed/failed
      * the param to be used once the operation will be pushed
      * on the listeners queue
-- 
2.26.2