Merge branch '1540-bind-aborts-when-queried-for-non-existing-domain-in-chaos-class' into 'master'

Resolve "bind 9.14.8 and 9.14.9 aborts when queried for non-existing domain in chaos class"

Closes #1569 and #1540

See merge request isc-projects/bind9!2843

CHANGES

@@ -1,3 +1,7 @@
+5350.	[bug]		When a view was configured with class CHAOS, the
+			server could crash while processing a query for a
+			non-existent record. [GL #1540]
+
 5349.	[bug]		Fix a race in task_pause/unpause. [GL #1571]
 
 5348.	[bug]		dnssec-settime -Psync was not being honoured.

bin/tests/system/resolver/ns1/chaostest.db

@@ -0,0 +1,5 @@
+$TTL		3600
+@		CHAOS SOA       @ @ 1970010100 86400 600 86400 300
+@		CHAOS NS        @
+version         CHAOS TXT       "CH 1.0"
+hostname        CHAOS TXT       "unknown"

bin/tests/system/resolver/ns1/named.conf.in

@@ -46,7 +46,10 @@ server fd92:7065:b8e:ffff::1000 {
  * "globalcache" before the recursive "default"/IN view is configured.
  */
 view "class" chaos {
-	match-clients { none; };
+	zone "chaostest" CHAOS {
+                type master;
+                file "chaostest.db";
+        };
 };
 
 /*

bin/tests/system/resolver/tests.sh

@@ -805,5 +805,13 @@ grep "running as: .* -m record,size,mctx " ns1/named.run > /dev/null || ret=1
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=`expr $status + $ret`
 
+n=`expr $n + 1`
+echo_i "checking NXDOMAIN is returned when querying non existing domain in CH class ($n)"
+ret=0
+$DIG $DIGOPTS @10.53.0.1 id.hostname txt ch > dig.ns1.out.${n} || ret=1
+grep "status: NXDOMAIN" dig.ns1.out.${n} > /dev/null || ret=1
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=`expr $status + $ret`
+
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1

lib/dns/view.c

@@ -1245,8 +1245,9 @@ dns_view_findzonecut(dns_view_t *view, const dns_name_t *name,
 			ztoptions |= DNS_ZTFIND_NOEXACT;
 		result = dns_zt_find(view->zonetable, name, ztoptions,
 				     NULL, &zone);
-	} else
+	} else {
 		result = ISC_R_NOTFOUND;
+	}
 	UNLOCK(&view->lock);
 	if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
 		result = dns_zone_getdb(zone, &db);
@@ -1261,12 +1262,15 @@ dns_view_findzonecut(dns_view_t *view, const dns_name_t *name,
 			 * We have a cache; try it.
 			 */
 			dns_db_attach(view->cachedb, &db);
-		} else {
+		} else if (use_hints && view->hints != NULL) {
 			/*
 			 * Maybe we have hints...
 			 */
 			try_hints = true;
 			goto finish;
+		} else {
+			result = DNS_R_NXDOMAIN;
+			goto cleanup;
 		}
 	} else if (result != ISC_R_SUCCESS) {
 		/*
@@ -1287,6 +1291,7 @@ dns_view_findzonecut(dns_view_t *view, const dns_name_t *name,
 			result = ISC_R_SUCCESS;
 		else if (result != ISC_R_SUCCESS)
 			goto cleanup;
+
 		if (use_cache && view->cachedb != NULL && db != view->hints) {
 			/*
 			 * We found an answer, but the cache may be better.
@@ -1327,13 +1332,16 @@ dns_view_findzonecut(dns_view_t *view, const dns_name_t *name,
 				 * have a zone delegation, so use it.
 				 */
 				use_zone = true;
-			} else {
+				result = ISC_R_SUCCESS;
+			} else if (use_hints && view->hints != NULL) {
 				/*
 				 * Maybe we have hints...
 				 */
 				try_hints = true;
+				result = ISC_R_SUCCESS;
+			} else {
+				result = DNS_R_NXDOMAIN;
 			}
-			result = ISC_R_SUCCESS;
 		} else {
 			/*
 			 * Something bad happened.
@@ -1358,7 +1366,7 @@ dns_view_findzonecut(dns_view_t *view, const dns_name_t *name,
 		if (sigrdataset != NULL &&
 		    dns_rdataset_isassociated(&zrdataset))
 			dns_rdataset_clone(&zsigrdataset, sigrdataset);
-	} else if (try_hints && use_hints && view->hints != NULL) {
+	} else if (try_hints) {
 		/*
 		 * We've found nothing so far, but we have hints.
 		 */