fix CVE-2021-25220

This commit is contained in:
jiangheng 2022-03-30 16:47:27 +08:00
parent e94219e77c
commit 561cbdf00a
2 changed files with 217 additions and 1 deletions

208
CVE-2021-25220.patch Normal file
View File

@ -0,0 +1,208 @@
Conflict: NA
Reference: https://gitlab.isc.org/isc-projects/bind9/-/commit/f1bc36f19362f9f2173bf9511e85781058f19c64
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index dd82f273a4d5a2d34edd1cbcba8c9daf78a71b34..677384b1081d060ccc0acc92e476eb7664577806 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -65,6 +65,8 @@
#include <dns/stats.h>
#include <dns/tsig.h>
#include <dns/validator.h>
+#include <dns/zone.h>
+
#ifdef WANT_QUERYTRACE
#define RTRACE(m) \
isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER, \
@@ -339,6 +341,8 @@ struct fetchctx {
dns_fetch_t *qminfetch;
dns_rdataset_t qminrrset;
dns_name_t qmindcname;
+ dns_fixedname_t fwdfname;
+ dns_name_t *fwdname;
/*%
* The number of events we're waiting for.
@@ -3766,6 +3770,7 @@ fctx_getaddresses(fetchctx_t *fctx, bool badcache) {
if (result == ISC_R_SUCCESS) {
fwd = ISC_LIST_HEAD(forwarders->fwdrs);
fctx->fwdpolicy = forwarders->fwdpolicy;
+ dns_name_copynf(domain, fctx->fwdname);
if (fctx->fwdpolicy == dns_fwdpolicy_only &&
isstrictsubdomain(domain, &fctx->domain))
{
@@ -5155,6 +5160,9 @@ fctx_create(dns_resolver_t *res, const dns_name_t *name, dns_rdatatype_t type,
fctx->restarts = 0;
fctx->querysent = 0;
fctx->referrals = 0;
+
+ fctx->fwdname = dns_fixedname_initname(&fctx->fwdfname);
+
TIME_NOW(&fctx->start);
fctx->timeouts = 0;
fctx->lamecount = 0;
@@ -5217,6 +5225,7 @@ fctx_create(dns_resolver_t *res, const dns_name_t *name, dns_rdatatype_t type,
fname, &forwarders);
if (result == ISC_R_SUCCESS) {
fctx->fwdpolicy = forwarders->fwdpolicy;
+ dns_name_copynf(fname, fctx->fwdname);
}
if (fctx->fwdpolicy != dns_fwdpolicy_only) {
@@ -7120,6 +7129,107 @@ mark_related(dns_name_t *name, dns_rdataset_t *rdataset, bool external,
}
}
+/*
+ * Returns true if 'name' is external to the namespace for which
+ * the server being queried can answer, either because it's not a
+ * subdomain or because it's below a forward declaration or a
+ * locally served zone.
+ */
+static inline bool
+name_external(const dns_name_t *name, dns_rdatatype_t type, fetchctx_t *fctx) {
+ isc_result_t result;
+ dns_forwarders_t *forwarders = NULL;
+ dns_fixedname_t fixed, zfixed;
+ dns_name_t *fname = dns_fixedname_initname(&fixed);
+ dns_name_t *zfname = dns_fixedname_initname(&zfixed);
+ dns_name_t *apex = NULL;
+ dns_name_t suffix;
+ dns_zone_t *zone = NULL;
+ unsigned int labels;
+ dns_namereln_t rel;
+
+ apex = ISFORWARDER(fctx->addrinfo) ? fctx->fwdname : &fctx->domain;
+
+ /*
+ * The name is outside the queried namespace.
+ */
+ rel = dns_name_fullcompare(name, apex, &(int){ 0 },
+ &(unsigned int){ 0U });
+ if (rel != dns_namereln_subdomain && rel != dns_namereln_equal) {
+ return (true);
+ }
+
+ /*
+ * If the record lives in the parent zone, adjust the name so we
+ * look for the correct zone or forward clause.
+ */
+ labels = dns_name_countlabels(name);
+ if (dns_rdatatype_atparent(type) && labels > 1U) {
+ dns_name_init(&suffix, NULL);
+ dns_name_getlabelsequence(name, 1, labels - 1, &suffix);
+ name = &suffix;
+ } else if (rel == dns_namereln_equal) {
+ /* If 'name' is 'apex', no further checking is needed. */
+ return (false);
+ }
+
+ /*
+ * If there is a locally served zone between 'apex' and 'name'
+ * then don't cache.
+ */
+ LOCK(&fctx->res->view->lock);
+ if (fctx->res->view->zonetable != NULL) {
+ unsigned int options = DNS_ZTFIND_NOEXACT | DNS_ZTFIND_MIRROR;
+ result = dns_zt_find(fctx->res->view->zonetable, name, options,
+ zfname, &zone);
+ if (zone != NULL) {
+ dns_zone_detach(&zone);
+ }
+ if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
+ if (dns_name_fullcompare(zfname, apex, &(int){ 0 },
+ &(unsigned int){ 0U }) ==
+ dns_namereln_subdomain)
+ {
+ UNLOCK(&fctx->res->view->lock);
+ return (true);
+ }
+ }
+ }
+ UNLOCK(&fctx->res->view->lock);
+
+ /*
+ * Look for a forward declaration below 'name'.
+ */
+ result = dns_fwdtable_find(fctx->res->view->fwdtable, name, fname,
+ &forwarders);
+
+ if (ISFORWARDER(fctx->addrinfo)) {
+ /*
+ * See if the forwarder declaration is better.
+ */
+ if (result == ISC_R_SUCCESS) {
+ return (!dns_name_equal(fname, fctx->fwdname));
+ }
+
+ /*
+ * If the lookup failed, the configuration must have
+ * changed: play it safe and don't cache.
+ */
+ return (true);
+ } else if (result == ISC_R_SUCCESS &&
+ forwarders->fwdpolicy == dns_fwdpolicy_only &&
+ !ISC_LIST_EMPTY(forwarders->fwdrs))
+ {
+ /*
+ * If 'name' is covered by a 'forward only' clause then we
+ * can't cache this repsonse.
+ */
+ return (true);
+ }
+
+ return (false);
+}
+
static isc_result_t
check_section(void *arg, const dns_name_t *addname, dns_rdatatype_t type,
dns_section_t section) {
@@ -7146,7 +7256,7 @@ check_section(void *arg, const dns_name_t *addname, dns_rdatatype_t type,
result = dns_message_findname(rctx->query->rmessage, section, addname,
dns_rdatatype_any, 0, &name, NULL);
if (result == ISC_R_SUCCESS) {
- external = !dns_name_issubdomain(name, &fctx->domain);
+ external = name_external(name, type, fctx);
if (type == dns_rdatatype_a) {
for (rdataset = ISC_LIST_HEAD(name->list);
rdataset != NULL;
@@ -8770,6 +8880,13 @@ rctx_answer_scan(respctx_t *rctx) {
break;
case dns_namereln_subdomain:
+ /*
+ * Don't accept DNAME from parent namespace.
+ */
+ if (name_external(name, dns_rdatatype_dname, fctx)) {
+ continue;
+ }
+
/*
* In-scope DNAME records must have at least
* as many labels as the domain being queried.
@@ -9083,13 +9200,11 @@ rctx_authority_positive(respctx_t *rctx) {
DNS_SECTION_AUTHORITY);
while (!done && result == ISC_R_SUCCESS) {
dns_name_t *name = NULL;
- bool external;
dns_message_currentname(rctx->query->rmessage,
DNS_SECTION_AUTHORITY, &name);
- external = !dns_name_issubdomain(name, &fctx->domain);
- if (!external) {
+ if (!name_external(name, dns_rdatatype_ns, fctx)) {
dns_rdataset_t *rdataset = NULL;
/*
@@ -9476,7 +9591,10 @@ rctx_authority_dnssec(respctx_t *rctx) {
}
if (!dns_name_issubdomain(name, &fctx->domain)) {
- /* Invalid name found; preserve it for logging later */
+ /*
+ * Invalid name found; preserve it for logging
+ * later.
+ */
rctx->found_name = name;
rctx->found_type = ISC_LIST_HEAD(name->list)->type;
continue;

View File

@ -30,7 +30,7 @@ Summary: The Berkeley Internet Name Domain (BIND) DNS (Domain Name System) serv
Name: bind Name: bind
License: MPLv2.0 License: MPLv2.0
Version: 9.16.23 Version: 9.16.23
Release: 2 Release: 3
Epoch: 32 Epoch: 32
Url: https://www.isc.org/downloads/bind/ Url: https://www.isc.org/downloads/bind/
# #
@ -80,6 +80,7 @@ Patch157:bind-9.11-fips-tests.patch
Patch164:bind-9.11-rh1666814.patch Patch164:bind-9.11-rh1666814.patch
Patch6000: CVE-2022-0396.patch Patch6000: CVE-2022-0396.patch
Patch6001: CVE-2021-25220.patch
%{?systemd_ordering} %{?systemd_ordering}
Requires: coreutils Requires: coreutils
@ -372,6 +373,7 @@ in HTML and PDF format.
%patch164 -p1 -b .rh1666814 %patch164 -p1 -b .rh1666814
%patch6000 -p1 %patch6000 -p1
%patch6001 -p1
%if %{with PKCS11} %if %{with PKCS11}
%patch135 -p1 -b .config-pkcs11 %patch135 -p1 -b .config-pkcs11
@ -1094,6 +1096,12 @@ fi;
%endif %endif
%changelog %changelog
* Wed Mar 30 2022 jiangheng<jiangheng12@huawei.com> - 9.16.23-3
- Type:CVE
- CVE:CVE-2021-25220
- SUG:NA
- DESC:fix CVE-2021-25220
* Wed Mar 30 2022 jiangheng<jiangheng12@huawei.com> - 9.16.23-2 * Wed Mar 30 2022 jiangheng<jiangheng12@huawei.com> - 9.16.23-2
- Type:CVE - Type:CVE
- CVE:CVE-2022-0396 - CVE:CVE-2022-0396