bind/backport-CVE-2021-25215.patch

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2021-05-26 15:31:30 +08:00
From c42cc79ef9a23d8273b273bb86a1c8c9995b28a0 Mon Sep 17 00:00:00 2001
From: UNKNOWN <>
Date: Tue, 27 Apr 2021 12:12:24 +0800
Subject: [PATCH v2 2/2] Fix CVE-2021-25215
Conflict:NA
Reference:https://downloads.isc.org/isc/bind9/private/40732ca6e4fcc9d0/patches/CVE-2021-25215.patch
diff --git a/bin/named/query.c b/bin/named/query.c
index 6e988f5..2e7700a 100644
--- a/bin/named/query.c
+++ b/bin/named/query.c
@@ -9092,10 +9092,17 @@ query_find(ns_client_t *client, dns_fetchevent_t *event, dns_rdatatype_t qtype)
if (noqname != NULL)
query_addnoqnameproof(client, noqname);
/*
- * We shouldn't ever fail to add 'rdataset'
- * because it's already in the answer.
+ * 'rdataset' will only be non-NULL here if the ANSWER section
+ * of the message to be sent to the client already contains an
+ * RRset with the same owner name and the same type as
+ * 'rdataset'. This should never happen, with one exception:
+ * when chasing DNAME records, one of the DNAME records placed
+ * in the ANSWER section may turn out to be the final answer to
+ * the client's query, but we have no way of knowing that until
+ * now. In such a case, 'rdataset' will be freed later, so we
+ * do not need to free it here.
*/
- INSIST(rdataset == NULL);
+ INSIST(rdataset == NULL || qtype == dns_rdatatype_dname);
}
addauth:
--
1.8.3.1