From b01d3ae3261264236504475a26c54ab45dd2175f Mon Sep 17 00:00:00 2001
From: Joseph Sutton <josephsutton@catalyst.net.nz>
Date: Fri, 27 Jan 2023 08:28:36 +1300
Subject: [PATCH 05/34] CVE-2023-0614 ldb: Add functions for handling
 inaccessible message elements

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15270

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Conflict: NA
Reference: https://attachments.samba.org/attachment.cgi?id=17821
---
 lib/ldb/common/ldb_msg.c     | 26 ++++++++++++++++++++++++++
 lib/ldb/include/ldb_module.h |  4 ++++
 2 files changed, 30 insertions(+)

diff --git a/lib/ldb/common/ldb_msg.c b/lib/ldb/common/ldb_msg.c
index 9cd7998e21c..cbc7e32b2ba 100644
--- a/lib/ldb/common/ldb_msg.c
+++ b/lib/ldb/common/ldb_msg.c
@@ -795,6 +795,32 @@ int ldb_msg_element_compare_name(struct ldb_message_element *el1,
 	return ldb_attr_cmp(el1->name, el2->name);
 }
 
+void ldb_msg_element_mark_inaccessible(struct ldb_message_element *el)
+{
+	el->flags |= LDB_FLAG_INTERNAL_INACCESSIBLE_ATTRIBUTE;
+}
+
+bool ldb_msg_element_is_inaccessible(const struct ldb_message_element *el)
+{
+	return (el->flags & LDB_FLAG_INTERNAL_INACCESSIBLE_ATTRIBUTE) != 0;
+}
+
+void ldb_msg_remove_inaccessible(struct ldb_message *msg)
+{
+	unsigned i;
+	unsigned num_del = 0;
+
+	for (i = 0; i < msg->num_elements; ++i) {
+		if (ldb_msg_element_is_inaccessible(&msg->elements[i])) {
+			++num_del;
+		} else if (num_del) {
+			msg->elements[i - num_del] = msg->elements[i];
+		}
+	}
+
+	msg->num_elements -= num_del;
+}
+
 /*
   convenience functions to return common types from a message
   these return the first value if the attribute is multi-valued
diff --git a/lib/ldb/include/ldb_module.h b/lib/ldb/include/ldb_module.h
index 4c7c85a17f0..8481fd3991a 100644
--- a/lib/ldb/include/ldb_module.h
+++ b/lib/ldb/include/ldb_module.h
@@ -513,6 +513,10 @@ struct ldb_extended_match_rule
 int ldb_register_extended_match_rule(struct ldb_context *ldb,
 				     const struct ldb_extended_match_rule *rule);
 
+void ldb_msg_element_mark_inaccessible(struct ldb_message_element *el);
+bool ldb_msg_element_is_inaccessible(const struct ldb_message_element *el);
+void ldb_msg_remove_inaccessible(struct ldb_message *msg);
+
 /*
  * these pack/unpack functions are exposed in the library for use by
  * ldb tools like ldbdump and for use in tests,
-- 
2.25.1