Merge branch '4652-dname-assertion' into 'main'

fix crash from NS target below DNAME

Closes #4652

See merge request isc-projects/bind9!8931

CHANGES

@@ -1,3 +1,6 @@
+6366.	[bug]		An assertion could be triggered in the QPDB cache when
+			encountering a delegation below a DNAME. [GL #4652]
+
 6365.	[placeholder]
 
 6364.	[protocol]	Add RESOLVER.ARPA to the built in empty zones.

bin/tests/system/chain/ans3/ans.pl

@@ -51,22 +51,22 @@ sub reply_handler {
     STDOUT->flush();
 
     if ($qname eq "example.broken") {
-        if ($qtype eq "SOA") {
+	if ($qtype eq "SOA") {
 	    my $rr = new Net::DNS::RR("$qname $ttl $qclass SOA . . 0 0 0 0 0");
 	    push @ans, $rr;
-        } elsif ($qtype eq "NS") {
+	} elsif ($qtype eq "NS") {
 	    my $rr = new Net::DNS::RR("$qname $ttl $qclass NS $nsname");
 	    push @ans, $rr;
 	    $rr = new Net::DNS::RR("$nsname $ttl $qclass A $localaddr");
 	    push @add, $rr;
-        }
+	}
-        $rcode = "NOERROR";
+	$rcode = "NOERROR";
     } elsif ($qname eq "cname-to-$synth2") {
-        my $rr = new Net::DNS::RR("$qname $ttl $qclass CNAME name.$synth2");
+	my $rr = new Net::DNS::RR("$qname $ttl $qclass CNAME name.$synth2");
 	push @ans, $rr;
-        $rr = new Net::DNS::RR("name.$synth2 $ttl $qclass CNAME name");
+	$rr = new Net::DNS::RR("name.$synth2 $ttl $qclass CNAME name");
 	push @ans, $rr;
-        $rr = new Net::DNS::RR("$synth2 $ttl $qclass DNAME .");
+	$rr = new Net::DNS::RR("$synth2 $ttl $qclass DNAME .");
 	push @ans, $rr;
 	$rcode = "NOERROR";
     } elsif ($qname eq "$synth" || $qname eq "$synth2") {
@@ -115,6 +115,30 @@ sub reply_handler {
 		push @ans, $rr;
 	}
 	$rcode = "NOERROR";
+    # The next few branches produce a zone with an illegal NS below a DNAME.
+    } elsif ($qname eq "jeff.dname") {
+	if ($qtype eq "SOA") {
+	    my $rr = new Net::DNS::RR("$qname $ttl $qclass SOA . . 0 0 0 0 0");
+	    push @ans, $rr;
+	} elsif ($qtype eq "NS") {
+	    my $rr = new Net::DNS::RR("$qname $ttl $qclass NS ns.jeff.dname.");
+	    push @ans, $rr;
+	    $rr = new Net::DNS::RR("$nsname $ttl $qclass A $localaddr");
+	    push @add, $rr;
+	} elsif ($qtype eq "DNAME") {
+	    my $rr = new Net::DNS::RR("$qname $ttl $qclass DNAME mutt.example.");
+	    push @ans, $rr;
+	}
+	$rcode = "NOERROR";
+    } elsif ($qname eq "ns.jeff.dname") {
+	if ($qtype eq "A") {
+		my $rr = new Net::DNS::RR("$qname $ttl $qclass A 10.53.0.3");
+		push @ans, $rr;
+	} elsif ($qtype eq "AAAA") {
+		my $rr = new Net::DNS::RR("jeff.dname. $ttl $qclass SOA . . 0 0 0 0 $ttl");
+		push @auth, $rr;
+	}
+	$rcode = "NOERROR";
     } else {
 	$rcode = "REFUSED";
     }

bin/tests/system/chain/ns1/root.db

@@ -30,6 +30,10 @@ ns3.example.broken.	A	10.53.0.3
 example.dname.		NS	ns3.example.dname.
 ns3.example.dname.	A	10.53.0.3
 
+; regression test for illegal NS below DNAME
+jeff.dname.		NS	ns.jeff.dname.
+ns.jeff.dname.	        A	10.53.0.3
+
 domain0.nil.		NS	ns2.domain0.nil
 domain1.nil.		NS	ns2.domain0.nil
 domain2.nil.		NS	ns2.domain0.nil

bin/tests/system/chain/ns2/example.db

@@ -48,6 +48,9 @@ signed-sub2		NS	ns2.sub2
 signed-sub2		DS	44137 8 2 1CB4F54E0B4F4F85109143113A3C679716A2377D86EB0907846A03FB 0C0A3927
 d			CNAME	d.signed-sub2
 
+mutt                    NS      ns5.mutt
+ns5.mutt                A       10.53.0.5
+
 ; long CNAME loop
 loop			CNAME	goop
 goop			CNAME	boop

bin/tests/system/chain/ns5/named.conf.in

@@ -40,3 +40,8 @@ zone "signed-sub5.example" {
 	type primary;
 	file "sub.db";
 };
+
+zone "mutt.example" {
+	type primary;
+	file "mutt.db";
+};

bin/tests/system/chain/tests.sh

@@ -626,5 +626,16 @@ grep 'status: NOERROR' dig.out.7.$n >/dev/null 2>&1 || ret=1
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=$((status + ret))
 
+# Regression test for GL #4652
+n=$((n + 1))
+echo_i "checking handling of illegal NS below DNAME ($n)"
+ret=0
+$DIG $DIGOPTS @10.53.0.7 DNAME jeff.dname. >dig.out.ns7.1.$n 2>&1
+grep 'status: NOERROR' dig.out.ns7.1.$n >/dev/null 2>&1 || ret=1
+$DIG $DIGOPTS @10.53.0.7 NS jeff.dname. >dig.out.ns7.2.$n 2>&1
+grep 'status: SERVFAIL' dig.out.ns7.2.$n >/dev/null 2>&1 || ret=1
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=$((status + ret))
+
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1

lib/dns/qpcache.c

@@ -1702,6 +1702,8 @@ find(dns_db_t *db, const dns_name_t *name, dns_dbversion_t *version,
 				encloser, (void *)&search DNS__DB_FLARG_PASS);
 			if (zcresult != DNS_R_CONTINUE) {
 				result = DNS_R_PARTIALMATCH;
+				dns_qpchain_node(&search.chain, i, foundname,
+						 NULL, NULL);
 				search.chain.len = i - 1;
 				node = encloser;
 				break;

lib/dns/qpzone.c

@@ -3453,6 +3453,8 @@ find(dns_db_t *db, const dns_name_t *name, dns_dbversion_t *version,
 		tresult = check_zonecut(n, &search DNS__DB_FLARG_PASS);
 		if (tresult != DNS_R_CONTINUE) {
 			result = tresult;
+			dns_qpchain_node(&search.chain, i, foundname, NULL,
+					 NULL);
 			search.chain.len = i - 1;
 			node = n;
 		}