From: Mark Andrews <marka@isc.org>
Date: Thu, 3 Feb 2005 05:07:35 +0000 (+0000)
Subject: 1808.   [bug]           zone.c:notify_zone() contained a race condition,
X-Git-Tag: v9.2.6b1~181^2~63
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=5cf146c586f69af7c65e4a4f612ae3ef6c9cf8de;p=thirdparty%2Fbind9.git

1808.   [bug]           zone.c:notify_zone() contained a race condition,
                        zone->db could change underneath it.  [RT #13511]
---

diff --git a/CHANGES b/CHANGES
index deb5105dab9..4e628031ec7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,7 @@
 1809.	[placeholder]	rt13463
 
-1808.	[placeholder]	rt13511
+1808.	[bug]		zone.c:notify_zone() contained a race condition,
+			zone->db could change underneath it.  [RT #13511]
 
 1807.	[placeholder]	rt13526
 
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 73cae607395..7d3a664eba7 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: zone.c,v 1.429 2005/01/11 23:10:05 marka Exp $ */
+/* $Id: zone.c,v 1.430 2005/02/03 05:07:35 marka Exp $ */
 
 #include <config.h>
 
@@ -3042,6 +3042,7 @@ zone_notify(dns_zone_t *zone, isc_time_t *now) {
 	dns_notifytype_t notifytype;
 	unsigned int flags = 0;
 	isc_boolean_t loggednotify = ISC_FALSE;
+	dns_db_t *db = NULL;
 
 	REQUIRE(DNS_ZONE_VALID(zone));
 
@@ -3061,6 +3062,13 @@ zone_notify(dns_zone_t *zone, isc_time_t *now) {
 	    zone->type != dns_zone_master)
 		return;
 
+	LOCK_ZONE(zone);
+	if (zone->db != NULL)
+		dns_db_attach(zone->db, &db);
+	UNLOCK_ZONE(zone);
+	if (db == NULL)
+		return;
+
 	origin = &zone->origin;
 
 	/*
@@ -3073,14 +3081,13 @@ zone_notify(dns_zone_t *zone, isc_time_t *now) {
 	/*
 	 * Get SOA RRset.
 	 */
-	dns_db_currentversion(zone->db, &version);
-	result = dns_db_findnode(zone->db, origin, ISC_FALSE, &node);
+	dns_db_currentversion(db, &version);
+	result = dns_db_findnode(db, origin, ISC_FALSE, &node);
 	if (result != ISC_R_SUCCESS)
 		goto cleanup1;
 
 	dns_rdataset_init(&soardset);
-	result = dns_db_findrdataset(zone->db, node, version,
-				     dns_rdatatype_soa,
+	result = dns_db_findrdataset(db, node, version, dns_rdatatype_soa,
 				     dns_rdatatype_none, 0, &soardset, NULL);
 	if (result != ISC_R_SUCCESS)
 		goto cleanup2;
@@ -3137,8 +3144,7 @@ zone_notify(dns_zone_t *zone, isc_time_t *now) {
 	 */
 
 	dns_rdataset_init(&nsrdset);
-	result = dns_db_findrdataset(zone->db, node, version,
-				     dns_rdatatype_ns,
+	result = dns_db_findrdataset(db, node, version, dns_rdatatype_ns,
 				     dns_rdatatype_none, 0, &nsrdset, NULL);
 	if (result != ISC_R_SUCCESS)
 		goto cleanup3;
@@ -3195,9 +3201,10 @@ zone_notify(dns_zone_t *zone, isc_time_t *now) {
 	if (dns_name_dynamic(&master))
 		dns_name_free(&master, zone->mctx);
  cleanup2:
-	dns_db_detachnode(zone->db, &node);
+	dns_db_detachnode(db, &node);
  cleanup1:
-	dns_db_closeversion(zone->db, &version, ISC_FALSE);
+	dns_db_closeversion(db, &version, ISC_FALSE);
+	dns_db_detach(&db);
 }
 
 /***