From: Mark Andrews <marka@isc.org>
Date: Wed, 12 Jun 2024 06:23:05 +0000 (+1000)
Subject: Check EDNS ZONEVERSION when parsing OPT record
X-Git-Tag: v9.21.7~34^2~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2c2b6755e98841325eddd12e37d422c8030ba3d;p=thirdparty%2Fbind9.git

Check EDNS ZONEVERSION when parsing OPT record
---

diff --git a/lib/dns/include/dns/message.h b/lib/dns/include/dns/message.h
index a467ea447f4..178a809ef28 100644
--- a/lib/dns/include/dns/message.h
+++ b/lib/dns/include/dns/message.h
@@ -102,7 +102,6 @@
 #define DNS_MESSAGEEXTFLAG_DO 0x8000U
 
 /*%< EDNS0 extended OPT codes */
-
 #define DNS_OPT_LLQ	       1  /*%< LLQ opt code */
 #define DNS_OPT_UL	       2  /*%< UL opt code */
 #define DNS_OPT_NSID	       3  /*%< NSID opt code */
@@ -129,7 +128,7 @@
  * options we know about. Extended DNS Errors may occur multiple times, see
  * DNS_EDE_MAX_ERRORS.
  */
-#define DNS_EDNSOPTIONS 8 + DNS_EDE_MAX_ERRORS
+#define DNS_EDNSOPTIONS 9 + DNS_EDE_MAX_ERRORS
 
 #define DNS_MESSAGE_REPLYPRESERVE	 (DNS_MESSAGEFLAG_RD | DNS_MESSAGEFLAG_CD)
 #define DNS_MESSAGEEXTFLAG_REPLYPRESERVE (DNS_MESSAGEEXTFLAG_DO)
diff --git a/lib/dns/rdata/generic/opt_41.c b/lib/dns/rdata/generic/opt_41.c
index 5c81b1546cb..b52288dc9b0 100644
--- a/lib/dns/rdata/generic/opt_41.c
+++ b/lib/dns/rdata/generic/opt_41.c
@@ -266,6 +266,21 @@ fromwire_opt(ARGS_FROMWIRE) {
 			}
 			isc_region_consume(&sregion, length);
 			break;
+		case DNS_OPT_ZONEVERSION:
+			if (length == 0) {
+				/* Request */
+				break;
+			}
+			/* Labels and Type */
+			if (length < 2) {
+				return DNS_R_OPTERR;
+			}
+			/* Type 0 (serial), length is 6. */
+			if (sregion.base[1] == 0 && length != 6) {
+				return DNS_R_OPTERR;
+			}
+			isc_region_consume(&sregion, length);
+			break;
 		default:
 			isc_region_consume(&sregion, length);
 			break;