From: Ondřej Surý <ondrej@sury.org>
Date: Fri, 10 Apr 2026 16:25:18 +0000 (+0200)
Subject: Tidy up cleanup path in check_signer()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dac6a57215dfc399fc3d8a51b3d0664e9dd19232;p=thirdparty%2Fbind9.git

Tidy up cleanup path in check_signer()

The cloned signature rdataset was not disassociated on the early
return taken when dns_dnssec_keyfromrdata() fails to parse the DNSKEY
public-key data.  In every current caller val->sigrdataset reaches
check_signer() rdatalist-backed, so dns_rdataset_clone() copies the
struct without taking any reference and dns_rdataset_disassociate()
is a no-op -- no memory is actually leaked today.  Hoist the key
parse out of the per-RRSIG loop and let the function fall through
to a single cleanup path, so the parse and the iteration cannot
diverge again.

Assisted-by: Claude:claude-opus-4-7
(cherry picked from commit 19f44a0aa376bace89d8ffaece546e1fc891a763)
---

diff --git a/lib/dns/validator.c b/lib/dns/validator.c
index 3ea4a640aec..44ff5a2094c 100644
--- a/lib/dns/validator.c
+++ b/lib/dns/validator.c
@@ -1730,6 +1730,12 @@ check_signer(dns_validator_t *val, dns_rdata_t *keyrdata, uint16_t keyid,
 	isc_result_t result;
 	dns_rdataset_t rdataset = DNS_RDATASET_INIT;
 
+	result = dns_dnssec_keyfromrdata(val->event->name, keyrdata,
+					 val->view->mctx, &dstkey);
+	if (result != ISC_R_SUCCESS) {
+		return result;
+	}
+
 	dns_rdataset_clone(val->event->sigrdataset, &rdataset);
 
 	for (result = dns_rdataset_first(&rdataset); result == ISC_R_SUCCESS;
@@ -1743,23 +1749,14 @@ check_signer(dns_validator_t *val, dns_rdata_t *keyrdata, uint16_t keyid,
 		if (keyid != sig.keyid || algorithm != sig.algorithm) {
 			continue;
 		}
-		if (dstkey == NULL) {
-			result = dns_dnssec_keyfromrdata(
-				val->event->name, keyrdata, val->view->mctx,
-				&dstkey);
-			if (result != ISC_R_SUCCESS) {
-				return result;
-			}
-		}
+
 		result = verify(val, dstkey, &rdata, sig.keyid);
 		if (result == ISC_R_SUCCESS) {
 			break;
 		}
 	}
 
-	if (dstkey != NULL) {
-		dst_key_free(&dstkey);
-	}
+	dst_key_free(&dstkey);
 	dns_rdataset_disassociate(&rdataset);
 
 	return result;