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[9.18] [CVE-2026-5946] sec: usr: Disable recursion, UPDATE, and NOTIFY for non-IN views

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Recursion, dynamic updates (UPDATE), and zone change notifications
(NOTIFY) are now disabled for views with a class other than IN
(such as CHAOS or HESIOD); authoritative service for non-IN zones
(e.g. version.bind in class CHAOS) continues to work as before.
Servers configured with recursion yes in a non-IN view will log a
warning at startup, and named-checkconf flags the same condition.
UPDATE and NOTIFY messages that specify the meta-classes ANY or NONE
in the question section are now rejected with FORMERR.

This addresses a set of closely related security issues collectively
identified as CVE-2026-5946. ISC would like to thank Mcsky23 for
bringing these issues to our attention.

Resolves-Vulnerability: CVE-2026-5946
Resolves: RHEL-177671
This commit is contained in:
Petr Menšík 2026-05-25 16:04:47 +02:00
parent 84ee08768a
commit 0d395adab1
2 changed files with 671 additions and 0 deletions
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@ -0,0 +1,668 @@
From 549972c7aab076fd4002aaa95eaebc81609c902d Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Tue, 3 Mar 2026 14:00:38 -0800
Subject: [PATCH] Disable recursion for non-IN classes
Force recursion off, and set allow-recursion/allow-recursion-on ACLs
to none, for views with a class other than IN. Log a configuration
warning if recursion is explicitly enabled for a non-IN view.
This addresses YWH-PGM40640-74 and YWH-PGM40640-75 by preventing any
attempt at recursive processing in a class-CHAOS view, ensuring that
server addresses used for recursive queries and received in recursive
responses are of the expected format.
Fixes: isc-projects/bind9#5780
Fixes: isc-projects/bind9#5781
(cherry picked from commit 7becff1a14684a68208c92b3b0315c045c05ad75)
(cherry picked from commit 401a6374b026afb76a7b22acc4a1402d21a7e77b)
Disable UPDATE and NOTIFY for non-IN classes
Return NOTIMP for UPDATE and NOTIFY requests received for views with a
class other than IN. Only QUERY is now supported for non-IN views such
as CHAOS.
When running dns dns_rdata_tostruct() with types that are only defined
for class IN, ensure that the class is correct before proceeding.
Add an assertion that any zone being updated is of class IN. (Note
that previously, a DLZ zone could have its class value set incorrectly
to NONE; this has been fixed.)
This addresses YWH-PGM40640-70 and YWH-PGM40640-73 (as well as any
similar problems that might have occurred in the future) by minimizing
the code paths that can be reached by rdata classes other than IN, so it
is safe for the implementation to assume that rdatatypes that are only
defined for class IN, such as SVCB or WKS, have been parsed and
validated, and not accepted as unknown/opaque data.
Fixes: isc-projects/bind9#5777
Fixes: isc-projects/bind9#5779
(cherry picked from commit a6d8e330ed6cf0021bff3f00aa1dc7a296f5aec0)
(cherry picked from commit 04092ed136c8a6db2b1059dcd32693d57a7bdc24)
Validate DNS message CLASS early in request processing
Reject requests with unsupported or misused CLASS values before
further processing. Only IN, CH, HS, RESERVED0 (for DNS Cookies),
ANY (for TKEY negotiation), and NONE (for DNS UPDATE) are accepted;
all other classes return NOTIMP. Misuse of NONE or ANY outside
their allowed contexts returns FORMERR.
This adds further protection against bugs of the same general class
as YWH-PGM40640-70 and YWH-PGM40640-73.
(cherry picked from commit 0a687451505037e9f9a850c9cb113aed4995b03f)
(cherry picked from commit b247dbb3506ef628a683d184fbc6a99fad45ed94)
Reject meta-classes in UPDATE and NOTIFY messages
NOTIFY and UPDATE messages must specify a data class in the
QUESTION/ZONE section. NONE and ANY are meta-classes and not
appropriate here. Return FORMERR if either is used.
Rejecting messages with a query class of NONE addresses YWH-PGM40640-72,
YWH-PGM40640-82, and YWH-PGM40640-83. Rejecting messages with a query
class of ANY addresses YWH-PGM40640-87, YWH-PGM40640-88, and
YWH-PGM40640-117.
Fixes: isc-projects/bind9#5778
Fixes: isc-projects/bind9#5782
Fixes: isc-projects/bind9#5783
Fixes: isc-projects/bind9#5797
Fixes: isc-projects/bind9#5798
Fixes: isc-projects/bind9#5853
(cherry picked from commit c66a1b1e1bfd6c79d7b9bc8d4a59e69f4faa1563)
(cherry picked from commit 185c10981b941bfa5b753b3624b6e11ccca8737f)
Skip "deny-answer-address" for non-IN addresses
Ensure that we don't attempt an ACL match for answer addresses
when handling a class-CHAOS zone. This is an additional line of
defense for YWH-PGM40640-74.
(cherry picked from commit e62673c765b52307c800e86f0185fe52b573c145)
(cherry picked from commit 772d1d5f905c819d7155e76a08c33218bfcc973e)
Test UPDATE behavior in CHAOS and other non-IN classes
Send various UPDATE requests that are known to have caused
crashes previously with deliberately misconfigured non-IN
zones; confirm that UPDATE is not processed.
(cherry picked from commit e2f7ba2a4b6e7e5dba2fb1a2c9b2f0323e9a88be)
(cherry picked from commit e5b3149b70ed24f7590b6bc08aad4492a00c2022)
---
bin/named/server.c | 42 ++++++-------------
bin/tests/system/allow-query/tests.sh | 2 +-
bin/tests/system/checkconf/tests.sh | 1 +
bin/tests/system/resolver/tests.sh | 8 ++--
bin/tests/system/unknown/tests.sh | 17 +++++---
lib/bind9/check.c | 22 ++++++++--
lib/dns/adb.c | 2 +-
lib/dns/message.c | 11 +++++
lib/dns/resolver.c | 7 ++++
lib/ns/client.c | 59 +++++++++++++++++++++++----
lib/ns/update.c | 41 ++++++++++---------
11 files changed, 143 insertions(+), 69 deletions(-)
diff --git a/bin/named/server.c b/bin/named/server.c
index a0a28c04a3..d95748305e 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -1901,10 +1901,12 @@ dlzconfigure_callback(dns_view_t *view, dns_dlzdb_t *dlzdb, dns_zone_t *zone) {
dns_rdataclass_t zclass = view->rdclass;
isc_result_t result;
+ dns_zone_setclass(zone, zclass);
result = dns_zonemgr_managezone(named_g_server->zonemgr, zone);
if (result != ISC_R_SUCCESS) {
return result;
}
+
dns_zone_setstats(zone, named_g_server->zonestats);
return named_zone_configure_writeable_dlz(dlzdb, zone, zclass, origin);
@@ -4429,6 +4431,7 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
obj = NULL;
result = named_config_get(maps, "max-cache-size", &obj);
INSIST(result == ISC_R_SUCCESS);
+
/*
* If "-T maxcachesize=..." is in effect, it overrides any other
* "max-cache-size" setting found in configuration, either implicit or
@@ -5139,34 +5142,15 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
}
/*
- * We have default hints for class IN if we need them.
+ * We have default root hints for class IN if we need them.
+ * Each view gets its own rootdb so a priming response only
+ * writes into that view's copy. Other classes don't support
+ * recursion and don't need hints.
*/
if (view->rdclass == dns_rdataclass_in && view->hints == NULL) {
dns_view_sethints(view, named_g_server->in_roothints);
}
- /*
- * If we still have no hints, this is a non-IN view with no
- * "hints zone" configured. Issue a warning, except if this
- * is a root server. Root servers never need to consult
- * their hints, so it's no point requiring users to configure
- * them.
- */
- if (view->hints == NULL) {
- dns_zone_t *rootzone = NULL;
- (void)dns_view_findzone(view, dns_rootname, &rootzone);
- if (rootzone != NULL) {
- dns_zone_detach(&rootzone);
- need_hints = false;
- }
- if (need_hints) {
- isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
- NAMED_LOGMODULE_SERVER, ISC_LOG_WARNING,
- "no root hints for view '%s'",
- view->name);
- }
- }
-
/*
* Configure the view's transports (DoT/DoH)
*/
@@ -5294,7 +5278,8 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
obj = NULL;
result = named_config_get(maps, "recursion", &obj);
INSIST(result == ISC_R_SUCCESS);
- view->recursion = cfg_obj_asboolean(obj);
+ view->recursion = (view->rdclass == dns_rdataclass_in &&
+ cfg_obj_asboolean(obj));
obj = NULL;
result = named_config_get(maps, "qname-minimization", &obj);
@@ -5394,14 +5379,13 @@ configure_view(dns_view_t *view, dns_viewlist_t *viewlist, cfg_obj_t *config,
CHECK(configure_view_acl(vconfig, config, NULL, "allow-query-cache-on",
NULL, actx, named_g_mctx, &view->cacheonacl));
- if (strcmp(view->name, "_bind") != 0 &&
- view->rdclass != dns_rdataclass_chaos)
- {
- /* named.conf only */
+ if (view->rdclass != dns_rdataclass_in) {
+ dns_acl_none(named_g_mctx, &view->recursionacl);
+ dns_acl_none(named_g_mctx, &view->recursiononacl);
+ } else {
CHECK(configure_view_acl(vconfig, config, NULL,
"allow-recursion", NULL, actx,
named_g_mctx, &view->recursionacl));
- /* named.conf only */
CHECK(configure_view_acl(vconfig, config, NULL,
"allow-recursion-on", NULL, actx,
named_g_mctx, &view->recursiononacl));
diff --git a/bin/tests/system/allow-query/tests.sh b/bin/tests/system/allow-query/tests.sh
index e59a1abe6b..46d2a78077 100644
--- a/bin/tests/system/allow-query/tests.sh
+++ b/bin/tests/system/allow-query/tests.sh
@@ -703,7 +703,7 @@ $DIG -p ${PORT} @10.53.1.2 d.normal.example a >dig.out.ns3.4.$n || ret=1
grep 'recursion requested but not available' dig.out.ns3.4.$n >/dev/null || ret=1
grep 'status: REFUSED' dig.out.ns3.4.$n >/dev/null || ret=1
grep 'EDE: 18 (Prohibited)' dig.out.ns3.4.$n >/dev/null || ret=1
-nextpart ns3/named.run | grep 'allow-recursion-on did not match' >/dev/null || ret=1
+nextpart ns3/named.run | grep 'allow-query-cache-on did not match' >/dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status + ret))
diff --git a/bin/tests/system/checkconf/tests.sh b/bin/tests/system/checkconf/tests.sh
index 7d222ed863..b2c955d312 100644
--- a/bin/tests/system/checkconf/tests.sh
+++ b/bin/tests/system/checkconf/tests.sh
@@ -543,6 +543,7 @@ $CHECKCONF -l good.conf \
| grep -v "is not implemented" \
| grep -v "is not recommended" \
| grep -v "no longer exists" \
+ | grep -v "recursion will be disabled" \
| grep -v "is obsolete" >checkconf.out$n || ret=1
diff good.zonelist checkconf.out$n >diff.out$n || ret=1
if [ $ret -ne 0 ]; then
diff --git a/bin/tests/system/resolver/tests.sh b/bin/tests/system/resolver/tests.sh
index 23b42f728c..b5d2cf8b46 100755
--- a/bin/tests/system/resolver/tests.sh
+++ b/bin/tests/system/resolver/tests.sh
@@ -948,10 +948,12 @@ if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status + ret))
n=$((n + 1))
-echo_i "checking NXDOMAIN is returned when querying non existing domain in CH class ($n)"
+echo_i "checking REFUSED is returned when querying non existing domain in CH class ($n)"
ret=0
-dig_with_opts @10.53.0.1 id.hostname txt ch >dig.ns1.out.${n} || ret=1
-grep "status: NXDOMAIN" dig.ns1.out.${n} >/dev/null || ret=1
+dig_with_opts @10.53.0.1 hostname.chaostest txt ch >dig.ns1.out.1.${n} || ret=1
+grep "status: NOERROR" dig.ns1.out.1.${n} >/dev/null || ret=1
+dig_with_opts @10.53.0.1 id.hostname txt ch >dig.ns1.out.2.${n} || ret=1
+grep "status: REFUSED" dig.ns1.out.2.${n} >/dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status + ret))
diff --git a/bin/tests/system/unknown/tests.sh b/bin/tests/system/unknown/tests.sh
index eb61f21f28..cbc2943f17 100644
--- a/bin/tests/system/unknown/tests.sh
+++ b/bin/tests/system/unknown/tests.sh
@@ -25,6 +25,11 @@ dig_cmd() {
"$DIG" $DIGOPTS "$@" | grep -v '^;'
}
+dig_full() {
+ # shellcheck disable=SC2086
+ "$DIG" $DIGOPTS "$@"
+}
+
n=$((n + 1))
echo_i "querying for various representations of an IN A record ($n)"
for i in 1 2 3 4 5 6 7 8 9 10 11 12; do
@@ -81,8 +86,8 @@ n=$((n + 1))
echo_i "querying for various representations of a CLASS10 TYPE1 record ($n)"
for i in 1 2; do
ret=0
- dig_cmd +short @10.53.0.1 a$i.example a class10 >dig.out.$i.test$n
- echo '\# 4 0A000001' | diff - dig.out.$i.test$n || ret=1
+ dig_full @10.53.0.1 a$i.example a class10 >dig.out.$i.test$n
+ grep -q "NOTIMP" dig.out.$i.test$n || ret=1
if [ $ret != 0 ]; then
echo_i "#$i failed"
fi
@@ -93,8 +98,8 @@ n=$((n + 1))
echo_i "querying for various representations of a CLASS10 TXT record ($n)"
for i in 1 2 3 4; do
ret=0
- dig_cmd +short @10.53.0.1 txt$i.example txt class10 >dig.out.$i.test$n
- echo '"hello"' | diff - dig.out.$i.test$n || ret=1
+ dig_full @10.53.0.1 txt$i.example txt class10 >dig.out.$i.test$n
+ grep -q "NOTIMP" dig.out.$i.test$n || ret=1
if [ $ret != 0 ]; then
echo_i "#$i failed"
fi
@@ -105,8 +110,8 @@ n=$((n + 1))
echo_i "querying for various representations of a CLASS10 TYPE123 record ($n)"
for i in 1 2; do
ret=0
- dig_cmd +short @10.53.0.1 unk$i.example type123 class10 >dig.out.$i.test$n
- echo '\# 1 00' | diff - dig.out.$i.test$n || ret=1
+ dig_full @10.53.0.1 unk$i.example type123 class10 >dig.out.$i.test$n
+ grep -q "NOTIMP" dig.out.$i.test$n || ret=1
if [ $ret != 0 ]; then
echo_i "#$i failed"
fi
diff --git a/lib/bind9/check.c b/lib/bind9/check.c
index cefc3eb3ac..13f3212d08 100644
--- a/lib/bind9/check.c
+++ b/lib/bind9/check.c
@@ -2789,13 +2789,17 @@ check_mirror_zone_notify(const cfg_obj_t *zoptions, const char *znamestr,
*/
static bool
check_recursion(const cfg_obj_t *config, const cfg_obj_t *voptions,
- const cfg_obj_t *goptions, isc_log_t *logctx,
- cfg_aclconfctx_t *actx, isc_mem_t *mctx) {
+ dns_rdataclass_t vclass, const cfg_obj_t *goptions,
+ isc_log_t *logctx, cfg_aclconfctx_t *actx, isc_mem_t *mctx) {
dns_acl_t *acl = NULL;
const cfg_obj_t *obj;
isc_result_t result;
bool retval = true;
+ if (vclass != dns_rdataclass_in) {
+ return false;
+ }
+
/*
* Check the "recursion" option first.
*/
@@ -3380,7 +3384,8 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
* contradicts the purpose of the former.
*/
if (ztype == CFG_ZONE_MIRROR &&
- !check_recursion(config, voptions, goptions, logctx, actx, mctx))
+ !check_recursion(config, voptions, zclass, goptions, logctx, actx,
+ mctx))
{
cfg_obj_log(zoptions, logctx, ISC_LOG_ERROR,
"zone '%s': mirror zones cannot be used if "
@@ -5215,6 +5220,17 @@ check_viewconf(const cfg_obj_t *config, const cfg_obj_t *voptions,
cfg_aclconfctx_create(mctx, &actx);
+ if (vclass != dns_rdataclass_in) {
+ if (check_recursion(config, voptions, dns_rdataclass_in,
+ options, logctx, actx, mctx))
+ {
+ cfg_obj_log(opts, logctx, ISC_LOG_WARNING,
+ "recursion will be disabled for "
+ "non-IN view '%s'",
+ viewname);
+ }
+ }
+
if (voptions != NULL) {
(void)cfg_map_get(voptions, "zone", &zones);
} else {
diff --git a/lib/dns/adb.c b/lib/dns/adb.c
index 8b6e153566..3da839cc12 100644
--- a/lib/dns/adb.c
+++ b/lib/dns/adb.c
@@ -938,7 +938,7 @@ import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset,
INSIST(DNS_ADB_VALID(adb));
rdtype = rdataset->type;
- INSIST((rdtype == dns_rdatatype_a) || (rdtype == dns_rdatatype_aaaa));
+ REQUIRE(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
addr_bucket = DNS_ADB_INVALIDBUCKET;
new_addresses_added = false;
diff --git a/lib/dns/message.c b/lib/dns/message.c
index f939fa94a7..1dc50c142a 100644
--- a/lib/dns/message.c
+++ b/lib/dns/message.c
@@ -1080,6 +1080,17 @@ getquestions(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx,
rdtype = isc_buffer_getuint16(source);
rdclass = isc_buffer_getuint16(source);
+ /*
+ * Notify and update messages need to specify the data class.
+ */
+ if ((msg->opcode == dns_opcode_update ||
+ msg->opcode == dns_opcode_notify) &&
+ (rdclass == dns_rdataclass_none ||
+ rdclass == dns_rdataclass_any))
+ {
+ DO_ERROR(DNS_R_FORMERR);
+ }
+
/*
* If this class is different than the one we already read,
* this is an error.
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 5c2294a0f2..1326cb3428 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -7249,6 +7249,13 @@ is_answeraddress_allowed(dns_view_t *view, dns_name_t *name,
}
}
+ /*
+ * deny-answer-address doesn't apply to non-IN classes.
+ */
+ if (rdataset->rdclass != dns_rdataclass_in) {
+ return true;
+ }
+
/*
* Otherwise, search the filter list for a match for each
* address record. If a match is found, the address should be
diff --git a/lib/ns/client.c b/lib/ns/client.c
index d8cd84bc5f..df4c570de2 100644
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -44,6 +44,7 @@
#include <dns/dispatch.h>
#include <dns/dnstap.h>
#include <dns/edns.h>
+#include <dns/enumclass.h>
#include <dns/events.h>
#include <dns/message.h>
#include <dns/peer.h>
@@ -2068,7 +2069,9 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult,
}
}
- if (client->message->rdclass == 0) {
+ char classbuf[DNS_RDATACLASS_FORMATSIZE];
+ switch (client->message->rdclass) {
+ case dns_rdataclass_reserved0:
if ((client->attributes & NS_CLIENTATTR_WANTCOOKIE) != 0 &&
client->message->opcode == dns_opcode_query &&
client->message->counts[DNS_SECTION_QUESTION] == 0U)
@@ -2087,12 +2090,46 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult,
return;
}
+ ns_client_dumpmessage(client,
+ "message class could not be determined");
+ ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR);
+ return;
+ case dns_rdataclass_in:
+ break;
+ case dns_rdataclass_chaos:
+ break;
+ case dns_rdataclass_hs:
+ break;
+ case dns_rdataclass_none:
+ if (client->message->opcode != dns_opcode_update) {
+ ns_client_dumpmessage(client,
+ "message class NONE can be only "
+ "used in DNS updates");
+ ns_client_error(client, DNS_R_FORMERR);
+ return;
+ }
+ break;
+ case dns_rdataclass_any:
+ /*
+ * Required for TKEY negotiation.
+ */
+ if (client->message->tkey == 0) {
+ ns_client_dumpmessage(client,
+ "message class ANY can be only "
+ "used for TKEY negotiation");
+ ns_client_error(client, DNS_R_FORMERR);
+ return;
+ }
+ break;
+ default:
+ dns_rdataclass_format(client->message->rdclass, classbuf,
+ sizeof(classbuf));
+ ns_client_dumpmessage(client, NULL);
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
- "message class could not be determined");
- ns_client_dumpmessage(client, "message class could not be "
- "determined");
- ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR);
+ "invalid message class: %s", classbuf);
+
+ ns_client_error(client, DNS_R_NOTIMP);
return;
}
@@ -2125,7 +2162,7 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult,
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"no matching view in class '%s'", classname);
- ns_client_dumpmessage(client, "no matching view in class");
+ ns_client_dumpmessage(client, NULL);
ns_client_extendederror(client, DNS_EDE_PROHIBITED, NULL);
ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_REFUSED);
return;
@@ -2322,6 +2359,10 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult,
break;
case dns_opcode_update:
CTRACE("update");
+ if (client->view->rdclass != dns_rdataclass_in) {
+ ns_client_error(client, DNS_R_NOTIMP);
+ break;
+ }
#ifdef HAVE_DNSTAP
dns_dt_send(client->view, DNS_DTTYPE_UQ, &client->peeraddr,
&client->destsockaddr, TCP_CLIENT(client), NULL,
@@ -2332,6 +2373,10 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult,
break;
case dns_opcode_notify:
CTRACE("notify");
+ if (client->view->rdclass != dns_rdataclass_in) {
+ ns_client_error(client, DNS_R_NOTIMP);
+ break;
+ }
ns_client_settimeout(client, 60);
ns_notify_start(client, handle);
break;
@@ -2758,7 +2803,7 @@ ns_client_dumpmessage(ns_client_t *client, const char *reason) {
int len = 1024;
isc_result_t result;
- if (!isc_log_wouldlog(ns_lctx, ISC_LOG_DEBUG(1))) {
+ if (!isc_log_wouldlog(ns_lctx, ISC_LOG_DEBUG(1)) || reason == NULL) {
return;
}
diff --git a/lib/ns/update.c b/lib/ns/update.c
index 248f6ed53b..84ba9c48d1 100644
--- a/lib/ns/update.c
+++ b/lib/ns/update.c
@@ -1026,7 +1026,9 @@ ssu_checkrr(void *data, rr_t *rr) {
RUNTIME_CHECK(result == ISC_R_SUCCESS);
target = &ptr.ptr;
}
- if (rr->rdata.type == dns_rdatatype_srv) {
+ if (rr->rdata.rdclass == dns_rdataclass_in &&
+ rr->rdata.type == dns_rdatatype_srv)
+ {
result = dns_rdata_tostruct(&rr->rdata, &srv, NULL);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
target = &srv.target;
@@ -1390,7 +1392,10 @@ replaces_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
return true;
}
}
- if (db_rr->type == dns_rdatatype_wks) {
+
+ if (db_rr->rdclass == dns_rdataclass_in &&
+ db_rr->type == dns_rdatatype_wks)
+ {
/*
* Compare the address and protocol fields only. These
* form the first five bytes of the RR data. Do a
@@ -1533,8 +1538,7 @@ failure:
* 'rdata', and 'ttl', respectively.
*/
static void
-get_current_rr(dns_message_t *msg, dns_section_t section,
- dns_rdataclass_t zoneclass, dns_name_t **name,
+get_current_rr(dns_message_t *msg, dns_section_t section, dns_name_t **name,
dns_rdata_t *rdata, dns_rdatatype_t *covers, dns_ttl_t *ttl,
dns_rdataclass_t *update_class) {
dns_rdataset_t *rdataset;
@@ -1550,7 +1554,7 @@ get_current_rr(dns_message_t *msg, dns_section_t section,
dns_rdataset_current(rdataset, rdata);
INSIST(dns_rdataset_next(rdataset) == ISC_R_NOMORE);
*update_class = rdata->rdclass;
- rdata->rdclass = zoneclass;
+ rdata->rdclass = dns_rdataclass_in;
}
/*%
@@ -1652,7 +1656,6 @@ send_update_event(ns_client_t *client, dns_zone_t *zone) {
dns_message_t *request = client->message;
isc_mem_t *mctx = client->manager->mctx;
dns_aclenv_t *env = client->manager->aclenv;
- dns_rdataclass_t zoneclass;
dns_rdatatype_t covers;
dns_name_t *zonename = NULL;
unsigned int *maxbytype = NULL;
@@ -1662,10 +1665,12 @@ send_update_event(ns_client_t *client, dns_zone_t *zone) {
CHECK(dns_zone_getdb(zone, &db));
zonename = dns_db_origin(db);
- zoneclass = dns_db_class(db);
dns_zone_getssutable(zone, &ssutable);
dns_db_currentversion(db, &ver);
+ /* Updates are only supported for class IN. */
+ INSIST(dns_zone_getclass(zone) == dns_rdataclass_in);
+
/*
* Update message processing can leak record existence information
* so check that we are allowed to query this zone. Additionally,
@@ -1716,13 +1721,13 @@ send_update_event(ns_client_t *client, dns_zone_t *zone) {
INSIST(ssutable == NULL || update < maxbytypelen);
- get_current_rr(request, DNS_SECTION_UPDATE, zoneclass, &name,
- &rdata, &covers, &ttl, &update_class);
+ get_current_rr(request, DNS_SECTION_UPDATE, &name, &rdata,
+ &covers, &ttl, &update_class);
if (!dns_name_issubdomain(name, zonename)) {
FAILC(DNS_R_NOTZONE, "update RR is outside zone");
}
- if (update_class == zoneclass) {
+ if (update_class == dns_rdataclass_in) {
/*
* Check for meta-RRs. The RFC2136 pseudocode says
* check for ANY|AXFR|MAILA|MAILB, but the text adds
@@ -1806,7 +1811,6 @@ send_update_event(ns_client_t *client, dns_zone_t *zone) {
}
if (update_class == dns_rdataclass_any &&
- zoneclass == dns_rdataclass_in &&
(rdata.type == dns_rdatatype_ptr ||
rdata.type == dns_rdatatype_srv))
{
@@ -2897,7 +2901,6 @@ update_action(isc_task_t *task, isc_event_t *event) {
isc_mem_t *mctx = client->mctx;
dns_rdatatype_t covers;
dns_message_t *request = client->message;
- dns_rdataclass_t zoneclass;
dns_name_t *zonename = NULL;
dns_ssutable_t *ssutable = NULL;
dns_fixedname_t tmpnamefixed;
@@ -2918,10 +2921,10 @@ update_action(isc_task_t *task, isc_event_t *event) {
CHECK(dns_zone_getdb(zone, &db));
zonename = dns_db_origin(db);
- zoneclass = dns_db_class(db);
dns_zone_getssutable(zone, &ssutable);
options = dns_zone_getoptions(zone);
+ INSIST(dns_zone_getclass(zone) == dns_rdataclass_in);
/*
* Get old and new versions now that queryacl has been checked.
*/
@@ -2942,8 +2945,8 @@ update_action(isc_task_t *task, isc_event_t *event) {
dns_rdataclass_t update_class;
bool flag;
- get_current_rr(request, DNS_SECTION_PREREQUISITE, zoneclass,
- &name, &rdata, &covers, &ttl, &update_class);
+ get_current_rr(request, DNS_SECTION_PREREQUISITE, &name, &rdata,
+ &covers, &ttl, &update_class);
if (ttl != 0) {
PREREQFAILC(DNS_R_FORMERR,
@@ -3006,7 +3009,7 @@ update_action(isc_task_t *task, isc_event_t *event) {
"prerequisite not satisfied");
}
}
- } else if (update_class == zoneclass) {
+ } else if (update_class == dns_rdataclass_in) {
/* "temp<rr.name, rr.type> += rr;" */
result = temp_append(&temp, name, &rdata);
if (result != ISC_R_SUCCESS) {
@@ -3068,10 +3071,10 @@ update_action(isc_task_t *task, isc_event_t *event) {
INSIST(ssutable == NULL || update < maxbytypelen);
- get_current_rr(request, DNS_SECTION_UPDATE, zoneclass, &name,
- &rdata, &covers, &ttl, &update_class);
+ get_current_rr(request, DNS_SECTION_UPDATE, &name, &rdata,
+ &covers, &ttl, &update_class);
- if (update_class == zoneclass) {
+ if (update_class == dns_rdataclass_in) {
/*
* RFC1123 doesn't allow MF and MD in master files.
*/
--
2.54.0

3
bind.spec
View File

@ -168,6 +168,8 @@ Patch232: bind-9.18-CVE-2026-1519.patch
Patch233: bind-9.18-CVE-2026-1519-test.patch
# https://gitlab.isc.org/isc-projects/bind9/-/commit/03ce21cf3099bd461f95ac1f4f22cce80ae1ba65
Patch234: bind-9.18-CVE-2026-3039.patch
# https://gitlab.isc.org/isc-projects/bind9/-/commit/7ce6ce37b1b04af0953ed2d3211587465085600e
Patch235: bind-9.18-CVE-2026-5946.patch
%{?systemd_ordering}
# https://fedoraproject.org/wiki/Changes/RPMSuportForSystemdSysusers
@ -971,6 +973,7 @@ fi;
%changelog
* Mon May 25 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.33-19
- Fix GSS-API resource leak (CVE-2026-3039)
- Invalid handling of CLASS != IN (CVE-2026-5946)
* Fri Mar 27 2026 Petr Menšík <pemensik@redhat.com> - 32:9.18.33-18
- Prevent Denial of Service via maliciously crafted DNSSEC-validated zone