bind9.18/bind-9.18-CVE-2024-11187.patch

From 7ded6b358ced23bb6214c7309cff0850b7d1b77d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Thu, 14 Nov 2024 10:37:29 +0100
Subject: [PATCH] Limit the additional processing for large RDATA sets

When answering queries, don't add data to the additional section if
the answer has more than 13 names in the RDATA.  This limits the
number of lookups into the database(s) during a single client query,
reducing query processing load.

Also, don't append any additional data to type=ANY queries. The
answer to ANY is already big enough.

(cherry picked from commit a1982cf1bb95c818aa7b58988b5611dec80f2408)
---
 bin/tests/system/additional/tests.sh |  2 +-
 lib/dns/include/dns/rdataset.h       | 10 +++++++++-
 lib/dns/rbtdb.c                      |  2 +-
 lib/dns/rdataset.c                   |  7 ++++++-
 lib/dns/resolver.c                   | 19 ++++++++++++-------
 lib/ns/query.c                       | 12 ++++++++----
 6 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/bin/tests/system/additional/tests.sh b/bin/tests/system/additional/tests.sh
index 193c9f9..e1b0cfb 100644
--- a/bin/tests/system/additional/tests.sh
+++ b/bin/tests/system/additional/tests.sh
@@ -279,7 +279,7 @@ n=$((n + 1))
 echo_i "testing with 'minimal-any no;' ($n)"
 ret=0
 $DIG $DIGOPTS -t ANY www.rt.example @10.53.0.1 >dig.out.$n || ret=1
-grep "ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2" dig.out.$n >/dev/null || ret=1
+grep "ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 1" dig.out.$n >/dev/null || ret=1
 if [ $ret -eq 1 ]; then
   echo_i "failed"
   status=$((status + 1))
diff --git a/lib/dns/include/dns/rdataset.h b/lib/dns/include/dns/rdataset.h
index f63591c..b28686a 100644
--- a/lib/dns/include/dns/rdataset.h
+++ b/lib/dns/include/dns/rdataset.h
@@ -54,6 +54,8 @@
 #include <dns/rdatastruct.h>
 #include <dns/types.h>
 
+#define DNS_RDATASET_MAXADDITIONAL 13
+
 ISC_LANG_BEGINDECLS
 
 typedef enum {
@@ -453,7 +455,8 @@ dns_rdataset_towirepartial(dns_rdataset_t   *rdataset,
 isc_result_t
 dns_rdataset_additionaldata(dns_rdataset_t	    *rdataset,
 			    const dns_name_t	    *owner_name,
-			    dns_additionaldatafunc_t add, void *arg);
+			    dns_additionaldatafunc_t add, void *arg,
+			    size_t limit);
 /*%<
  * For each rdata in rdataset, call 'add' for each name and type in the
  * rdata which is subject to additional section processing.
@@ -472,10 +475,15 @@ dns_rdataset_additionaldata(dns_rdataset_t	    *rdataset,
  *\li	If a call to dns_rdata_additionaldata() is not successful, the
  *	result returned will be the result of dns_rdataset_additionaldata().
  *
+ *\li	If 'limit' is non-zero and the number of the rdatasets is larger
+ *	than 'limit', no additional data will be processed.
+ *
  * Returns:
  *
  *\li	#ISC_R_SUCCESS
  *
+ *\li	#DNS_R_TOOMANYRECORDS in case rdataset count is larger than 'limit'
+ *
  *\li	Any error that dns_rdata_additionaldata() can return.
  */
 
diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 5c2f0b2..c4db047 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -10317,7 +10317,7 @@ no_glue:
 	idx = hash_32(hash, rbtversion->glue_table_bits);
 
 	(void)dns_rdataset_additionaldata(rdataset, dns_rootname,
-					  glue_nsdname_cb, &ctx);
+					  glue_nsdname_cb, &ctx, 0);
 
 	cur = isc_mem_get(rbtdb->common.mctx, sizeof(*cur));
 
diff --git a/lib/dns/rdataset.c b/lib/dns/rdataset.c
index 4d48203..0b450a9 100644
--- a/lib/dns/rdataset.c
+++ b/lib/dns/rdataset.c
@@ -577,7 +577,8 @@ dns_rdataset_towire(dns_rdataset_t *rdataset, const dns_name_t *owner_name,
 isc_result_t
 dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
 			    const dns_name_t *owner_name,
-			    dns_additionaldatafunc_t add, void *arg) {
+			    dns_additionaldatafunc_t add, void *arg,
+			    size_t limit) {
 	dns_rdata_t rdata = DNS_RDATA_INIT;
 	isc_result_t result;
 
@@ -589,6 +590,10 @@ dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
 	REQUIRE(DNS_RDATASET_VALID(rdataset));
 	REQUIRE((rdataset->attributes & DNS_RDATASETATTR_QUESTION) == 0);
 
+	if (limit != 0 && dns_rdataset_count(rdataset) > limit) {
+		return DNS_R_TOOMANYRECORDS;
+	}
+
 	result = dns_rdataset_first(rdataset);
 	if (result != ISC_R_SUCCESS) {
 		return (result);
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index f8f53d2..bb0bfa1 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -8904,7 +8904,7 @@ rctx_answer_any(respctx_t *rctx) {
 		rdataset->trust = rctx->trust;
 
 		(void)dns_rdataset_additionaldata(rdataset, rctx->aname,
-						  check_related, rctx);
+						  check_related, rctx, 0);
 	}
 
 	return (ISC_R_SUCCESS);
@@ -8952,7 +8952,7 @@ rctx_answer_match(respctx_t *rctx) {
 	rctx->ardataset->attributes |= DNS_RDATASETATTR_CACHE;
 	rctx->ardataset->trust = rctx->trust;
 	(void)dns_rdataset_additionaldata(rctx->ardataset, rctx->aname,
-					  check_related, rctx);
+					  check_related, rctx, 0);
 
 	for (sigrdataset = ISC_LIST_HEAD(rctx->aname->list);
 	     sigrdataset != NULL;
@@ -9159,7 +9159,7 @@ rctx_authority_positive(respctx_t *rctx) {
 					 */
 					(void)dns_rdataset_additionaldata(
 						rdataset, name, check_related,
-						rctx);
+						rctx, 0);
 					done = true;
 				}
 			}
@@ -9666,8 +9666,12 @@ rctx_referral(respctx_t *rctx) {
 	 */
 	INSIST(rctx->ns_rdataset != NULL);
 	FCTX_ATTR_SET(fctx, FCTX_ATTR_GLUING);
+
+	/*
+	 * Mark the glue records in the additional section to be cached.
+	 */
 	(void)dns_rdataset_additionaldata(rctx->ns_rdataset, rctx->ns_name,
-					  check_related, rctx);
+					  check_related, rctx, 0);
 #if CHECK_FOR_GLUE_IN_ANSWER
 	/*
 	 * Look in the answer section for "glue" that is incorrectly
@@ -9679,8 +9683,9 @@ rctx_referral(respctx_t *rctx) {
 	if (rctx->glue_in_answer &&
 	    (fctx->type == dns_rdatatype_aaaa || fctx->type == dns_rdatatype_a))
 	{
-		(void)dns_rdataset_additionaldata(
-			rctx->ns_rdataset, rctx->ns_name, check_answer, fctx);
+		(void)dns_rdataset_additionaldata(rctx->ns_rdataset,
+						  rctx->ns_name, check_answer,
+						  fctx, 0);
 	}
 #endif /* if CHECK_FOR_GLUE_IN_ANSWER */
 	FCTX_ATTR_CLR(fctx, FCTX_ATTR_GLUING);
@@ -9782,7 +9787,7 @@ again:
 			if (CHASE(rdataset)) {
 				rdataset->attributes &= ~DNS_RDATASETATTR_CHASE;
 				(void)dns_rdataset_additionaldata(
-					rdataset, name, check_related, rctx);
+					rdataset, name, check_related, rctx, 0);
 				rescan = true;
 			}
 		}
diff --git a/lib/ns/query.c b/lib/ns/query.c
index 5549e20..ded1eae 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -2094,7 +2094,8 @@ addname:
 	if (trdataset != NULL && dns_rdatatype_followadditional(type)) {
 		if (client->additionaldepth++ < client->view->max_restarts) {
 			eresult = dns_rdataset_additionaldata(
-				trdataset, fname, query_additional_cb, qctx);
+				trdataset, fname, query_additional_cb, qctx,
+				DNS_RDATASET_MAXADDITIONAL);
 		}
 		client->additionaldepth--;
 	}
@@ -2194,7 +2195,7 @@ regular:
 	 * We don't care if dns_rdataset_additionaldata() fails.
 	 */
 	(void)dns_rdataset_additionaldata(rdataset, name, query_additional_cb,
-					  qctx);
+					  qctx, DNS_RDATASET_MAXADDITIONAL);
 	CTRACE(ISC_LOG_DEBUG(3), "query_additional: done");
 }
 
@@ -2220,7 +2221,8 @@ query_addrrset(query_ctx_t *qctx, dns_name_t **namep,
 	 * To the current response for 'client', add the answer RRset
 	 * '*rdatasetp' and an optional signature set '*sigrdatasetp', with
 	 * owner name '*namep', to section 'section', unless they are
-	 * already there.  Also add any pertinent additional data.
+	 * already there.  Also add any pertinent additional data, unless
+	 * the query was for type ANY.
 	 *
 	 * If 'dbuf' is not NULL, then '*namep' is the name whose data is
 	 * stored in 'dbuf'.  In this case, query_addrrset() guarantees that
@@ -2275,7 +2277,9 @@ query_addrrset(query_ctx_t *qctx, dns_name_t **namep,
 	 */
 	query_addtoname(mname, rdataset);
 	query_setorder(qctx, mname, rdataset);
-	query_additional(qctx, mname, rdataset);
+	if (qctx->qtype != dns_rdatatype_any) {
+		query_additional(qctx, mname, rdataset);
+	}
 
 	/*
 	 * Note: we only add SIGs if we've added the type they cover, so
-- 
2.48.1