3693. [security] memcpy was incorrectly called with overlapping

                        ranges resulting in malformed names being generated
                        on some platforms.  This could cause INSIST failures
                        when serving NSEC3 signed zones.  [RT #35120]

diff --git a/CHANGES b/CHANGES
index fb1724d3f3b408218f7ef648fcd5172afb3f9d27..7044c024f49cad3028c0090cdcf2dc3c1296c04a 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,8 +1,7 @@
 3693.  [security]      memcpy was incorrectly called with overlapping
-                       ranges resulting a malformed names being generated
-                       on some platforms.  This was subsequently detected
-                       resulting in INSIST failures when serving NSEC3
-                       signed zones.  [RT #35120]
+                       ranges resulting in malformed names being generated
+                       on some platforms.  This could cause INSIST failures
+                       when serving NSEC3 signed zones.  [RT #35120]
 
 3692.  [bug]           Two calls to dns_db_getoriginnode were fatal if there
                        was no data at the node. [RT #35080]

diff --git a/bin/named/query.c b/bin/named/query.c
index fb0259732aeb76d1bfd8bb32d73b6fc69777019e..1eede63b78420311e66036fee5f16c739d368517 100644 (file)
--- a/bin/named/query.c
+++ b/bin/named/query.c
@@ -5659,8 +5659,7 @@ query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
        dns_fixedname_t fixed;
        dns_hash_t hash;
        dns_name_t name;
-       int order;
-       unsigned int count;
+       unsigned int skip = 0, labels;
        dns_rdata_nsec3_t nsec3;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_boolean_t optout;
@@ -5675,6 +5674,7 @@ query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
 
        dns_name_init(&name, NULL);
        dns_name_clone(qname, &name);
+       labels = dns_name_countlabels(&name);
        dns_clientinfomethods_init(&cm, ns_client_sourceip);
        dns_clientinfo_init(&ci, client);
 
@@ -5708,13 +5708,14 @@ query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
                dns_rdata_reset(&rdata);
                optout = ISC_TF((nsec3.flags & DNS_NSEC3FLAG_OPTOUT) != 0);
                if (found != NULL && optout &&
-                   dns_name_fullcompare(&name, dns_db_origin(db), &order,
-                                        &count) == dns_namereln_subdomain) {
+                   dns_name_issubdomain(&name, dns_db_origin(db)))
+               {
                        dns_rdataset_disassociate(rdataset);
                        if (dns_rdataset_isassociated(sigrdataset))
                                dns_rdataset_disassociate(sigrdataset);
-                       count = dns_name_countlabels(&name) - 1;
-                       dns_name_getlabelsequence(&name, 1, count, &name);
+                       skip++;
+                       dns_name_getlabelsequence(qname, skip, labels - skip,
+                                                 &name);
                        ns_client_log(client, DNS_LOGCATEGORY_DNSSEC,
                                      NS_LOGMODULE_QUERY, ISC_LOG_DEBUG(3),
                                      "looking for closest provable encloser");
@@ -5732,7 +5733,11 @@ query_findclosestnsec3(dns_name_t *qname, dns_db_t *db,
                ns_client_log(client, DNS_LOGCATEGORY_DNSSEC,
                              NS_LOGMODULE_QUERY, ISC_LOG_WARNING,
                              "expected covering NSEC3, got an exact match");
-       if (found != NULL)
+       if (found == qname) {
+               if (skip != 0U)
+                       dns_name_getlabelsequence(qname, skip, labels - skip,
+                                                 found);
+       } else if (found != NULL)
                dns_name_copy(&name, found, NULL);
        return;
 }