--- /dev/null
+CVE-2016-2088
+
+Backport commit d7ff9a1c41bf0ba9773cb3adb08b48b9fd57c956 from the
+v9_10_3_patch branch.
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2088
+https://kb.isc.org/article/AA-01351
+
+CVE: CVE-2016-2088
+Upstream-Status: Backport
+Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
+
+
+Original commit message from Mark Andrews <marka@isc.org> below:
+
+4322. [security] Duplicate EDNS COOKIE options in a response could
+ trigger an assertion failure. (CVE-2016-2088)
+ [RT #41809]
+
+(cherry picked from commit 455c0848f80a8acda27aad1466c72987cafaa029)
+(cherry picked from commit 7cd300abd6ee8b8ee8730593daf742ba53f90bc3)
+---
+ CHANGES | 4 ++++
+ bin/dig/dighost.c | 9 +++++++++
+ bin/named/client.c | 33 +++++++++++++++++++++++----------
+ doc/arm/notes.xml | 7 +++++++
+ lib/dns/resolver.c | 14 +++++++++++++-
+ 5 files changed, 56 insertions(+), 11 deletions(-)
+
+diff --git a/CHANGES b/CHANGES
+index c5b5d2b..d2e3360 100644
+--- a/CHANGES
++++ b/CHANGES
+@@ -1,3 +1,7 @@
++4322. [security] Duplicate EDNS COOKIE options in a response could
++ trigger an assertion failure. (CVE-2016-2088)
++ [RT #41809]
++
+ 4319. [security] Fix resolver assertion failure due to improper
+ DNAME handling when parsing fetch reply messages.
+ (CVE-2016-1286) [RT #41753]
+diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
+index ca82f8e..340904f 100644
+--- a/bin/dig/dighost.c
++++ b/bin/dig/dighost.c
+@@ -3458,6 +3458,7 @@ process_opt(dig_lookup_t *l, dns_message_t *msg) {
+ isc_buffer_t optbuf;
+ isc_uint16_t optcode, optlen;
+ dns_rdataset_t *opt = msg->opt;
++ isc_boolean_t seen_cookie = ISC_FALSE;
+
+ result = dns_rdataset_first(opt);
+ if (result == ISC_R_SUCCESS) {
+@@ -3470,7 +3471,15 @@ process_opt(dig_lookup_t *l, dns_message_t *msg) {
+ optlen = isc_buffer_getuint16(&optbuf);
+ switch (optcode) {
+ case DNS_OPT_COOKIE:
++ /*
++ * Only process the first cookie option.
++ */
++ if (seen_cookie) {
++ isc_buffer_forward(&optbuf, optlen);
++ break;
++ }
+ process_sit(l, msg, &optbuf, optlen);
++ seen_cookie = ISC_TRUE;
+ break;
+ default:
+ isc_buffer_forward(&optbuf, optlen);
+diff --git a/bin/named/client.c b/bin/named/client.c
+index 683305c..0d7331a 100644
+--- a/bin/named/client.c
++++ b/bin/named/client.c
+@@ -120,7 +120,10 @@
+ */
+ #endif
+
+-#define SIT_SIZE 24U /* 8 + 4 + 4 + 8 */
++#define COOKIE_SIZE 24U /* 8 + 4 + 4 + 8 */
++
++#define WANTNSID(x) (((x)->attributes & NS_CLIENTATTR_WANTNSID) != 0)
++#define WANTEXPIRE(x) (((x)->attributes & NS_CLIENTATTR_WANTEXPIRE) != 0)
+
+ /*% nameserver client manager structure */
+ struct ns_clientmgr {
+@@ -1395,7 +1398,7 @@ ns_client_addopt(ns_client_t *client, dns_message_t *message,
+ {
+ char nsid[BUFSIZ], *nsidp;
+ #ifdef ISC_PLATFORM_USESIT
+- unsigned char sit[SIT_SIZE];
++ unsigned char sit[COOKIE_SIZE];
+ #endif
+ isc_result_t result;
+ dns_view_t *view;
+@@ -1420,7 +1423,7 @@ ns_client_addopt(ns_client_t *client, dns_message_t *message,
+ flags = client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE;
+
+ /* Set EDNS options if applicable */
+- if ((client->attributes & NS_CLIENTATTR_WANTNSID) != 0 &&
++ if (WANTNSID(client) &&
+ (ns_g_server->server_id != NULL ||
+ ns_g_server->server_usehostname)) {
+ if (ns_g_server->server_usehostname) {
+@@ -1453,7 +1456,7 @@ ns_client_addopt(ns_client_t *client, dns_message_t *message,
+
+ INSIST(count < DNS_EDNSOPTIONS);
+ ednsopts[count].code = DNS_OPT_COOKIE;
+- ednsopts[count].length = SIT_SIZE;
++ ednsopts[count].length = COOKIE_SIZE;
+ ednsopts[count].value = sit;
+ count++;
+ }
+@@ -1661,19 +1664,26 @@ compute_sit(ns_client_t *client, isc_uint32_t when, isc_uint32_t nonce,
+
+ static void
+ process_sit(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
+- unsigned char dbuf[SIT_SIZE];
++ unsigned char dbuf[COOKIE_SIZE];
+ unsigned char *old;
+ isc_stdtime_t now;
+ isc_uint32_t when;
+ isc_uint32_t nonce;
+ isc_buffer_t db;
+
++ /*
++ * If we have already seen a ECS option skip this ECS option.
++ */
++ if ((client->attributes & NS_CLIENTATTR_WANTSIT) != 0) {
++ isc_buffer_forward(buf, optlen);
++ return;
++ }
+ client->attributes |= NS_CLIENTATTR_WANTSIT;
+
+ isc_stats_increment(ns_g_server->nsstats,
+ dns_nsstatscounter_sitopt);
+
+- if (optlen != SIT_SIZE) {
++ if (optlen != COOKIE_SIZE) {
+ /*
+ * Not our token.
+ */
+@@ -1717,14 +1727,13 @@ process_sit(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
+ isc_buffer_init(&db, dbuf, sizeof(dbuf));
+ compute_sit(client, when, nonce, &db);
+
+- if (!isc_safe_memequal(old, dbuf, SIT_SIZE)) {
++ if (!isc_safe_memequal(old, dbuf, COOKIE_SIZE)) {
+ isc_stats_increment(ns_g_server->nsstats,
+ dns_nsstatscounter_sitnomatch);
+ return;
+ }
+ isc_stats_increment(ns_g_server->nsstats,
+ dns_nsstatscounter_sitmatch);
+-
+ client->attributes |= NS_CLIENTATTR_HAVESIT;
+ }
+ #endif
+@@ -1783,7 +1792,9 @@ process_opt(ns_client_t *client, dns_rdataset_t *opt) {
+ optlen = isc_buffer_getuint16(&optbuf);
+ switch (optcode) {
+ case DNS_OPT_NSID:
+- isc_stats_increment(ns_g_server->nsstats,
++ if (!WANTNSID(client))
++ isc_stats_increment(
++ ns_g_server->nsstats,
+ dns_nsstatscounter_nsidopt);
+ client->attributes |= NS_CLIENTATTR_WANTNSID;
+ isc_buffer_forward(&optbuf, optlen);
+@@ -1794,7 +1805,9 @@ process_opt(ns_client_t *client, dns_rdataset_t *opt) {
+ break;
+ #endif
+ case DNS_OPT_EXPIRE:
+- isc_stats_increment(ns_g_server->nsstats,
++ if (!WANTEXPIRE(client))
++ isc_stats_increment(
++ ns_g_server->nsstats,
+ dns_nsstatscounter_expireopt);
+ client->attributes |= NS_CLIENTATTR_WANTEXPIRE;
+ isc_buffer_forward(&optbuf, optlen);
+diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
+index ebf4f55..095eb5b 100644
+--- a/doc/arm/notes.xml
++++ b/doc/arm/notes.xml
+@@ -51,6 +51,13 @@
+ <title>Security Fixes</title>
+ <itemizedlist>
+ <listitem>
++ <para>
++ Duplicate EDNS COOKIE options in a response could trigger
++ an assertion failure. This flaw is disclosed in CVE-2016-2088.
++ [RT #41809]
++ </para>
++ </listitem>
++ <listitem>
+ <para>
+ Specific APL data could trigger an INSIST. This flaw
+ was discovered by Brian Mitchell and is disclosed in
+diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
+index a797e3f..ba1ae23 100644
+--- a/lib/dns/resolver.c
++++ b/lib/dns/resolver.c
+@@ -7502,7 +7502,9 @@ process_opt(resquery_t *query, dns_rdataset_t *opt) {
+ unsigned char *sit;
+ dns_adbaddrinfo_t *addrinfo;
+ unsigned char cookie[8];
++ isc_boolean_t seen_cookie = ISC_FALSE;
+ #endif
++ isc_boolean_t seen_nsid = ISC_FALSE;
+
+ result = dns_rdataset_first(opt);
+ if (result == ISC_R_SUCCESS) {
+@@ -7516,14 +7518,23 @@ process_opt(resquery_t *query, dns_rdataset_t *opt) {
+ INSIST(optlen <= isc_buffer_remaininglength(&optbuf));
+ switch (optcode) {
+ case DNS_OPT_NSID:
+- if (query->options & DNS_FETCHOPT_WANTNSID)
++ if (!seen_nsid &&
++ query->options & DNS_FETCHOPT_WANTNSID)
+ log_nsid(&optbuf, optlen, query,
+ ISC_LOG_DEBUG(3),
+ query->fctx->res->mctx);
+ isc_buffer_forward(&optbuf, optlen);
++ seen_nsid = ISC_TRUE;
+ break;
+ #ifdef ISC_PLATFORM_USESIT
+ case DNS_OPT_COOKIE:
++ /*
++ * Only process the first cookie option.
++ */
++ if (seen_cookie) {
++ isc_buffer_forward(&optbuf, optlen);
++ break;
++ }
+ sit = isc_buffer_current(&optbuf);
+ compute_cc(query, cookie, sizeof(cookie));
+ INSIST(query->fctx->rmessage->sitbad == 0 &&
+@@ -7541,6 +7552,7 @@ process_opt(resquery_t *query, dns_rdataset_t *opt) {
+ isc_buffer_forward(&optbuf, optlen);
+ inc_stats(query->fctx->res,
+ dns_resstatscounter_sitin);
++ seen_cookie = ISC_TRUE;
+ break;
+ #endif
+ default:
+--
+2.1.4
+
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
