From: Mark Andrews <marka@isc.org>
Date: Thu, 29 Feb 2024 03:00:58 +0000 (+1100)
Subject: Restore the disassociate call to before the fetch
X-Git-Tag: v9.19.22~11^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ff55e13e867b030e768d537c83ec84427b44403;p=thirdparty%2Fbind9.git

Restore the disassociate call to before the fetch

[GL #3709] reordered the dns_rdataset_disassociate call to after
the dns_resolver_createfetch call resulting in qctx->nsrrset still
being associated when dns_resolver_createfetch is called in
resume_dslookup (7e4e125e).  Revert that part of the change and add
comments as to why the multiple dns_rdataset_disassociate calls are
where they are.
---

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 635b9ea0190..0570ff45a2b 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -6964,7 +6964,7 @@ resume_dslookup(void *arg) {
 	}
 
 	/* Preserve data from resp before freeing it. */
-	frdataset = resp->rdataset;
+	frdataset = resp->rdataset; /* a.k.a. fctx->nsrrset */
 	result = resp->result;
 	isc_mem_putanddetach(&resp->mctx, resp, sizeof(*resp));
 
@@ -6988,6 +6988,13 @@ resume_dslookup(void *arg) {
 		}
 		dns_rdataset_clone(frdataset, &fctx->nameservers);
 
+		/*
+		 * Disassociate now the NS's are saved.
+		 */
+		if (dns_rdataset_isassociated(frdataset)) {
+			dns_rdataset_disassociate(frdataset);
+		}
+
 		fctx->ns_ttl = fctx->nameservers.ttl;
 		fctx->ns_ttl_ok = true;
 		log_ns_ttl(fctx, "resume_dslookup");
@@ -7005,10 +7012,21 @@ resume_dslookup(void *arg) {
 
 	case ISC_R_SHUTTINGDOWN:
 	case ISC_R_CANCELED:
-		/* Don't try anymore */
+		/* Don't try anymore. */
+		/* Can't be done in cleanup. */
+		if (dns_rdataset_isassociated(frdataset)) {
+			dns_rdataset_disassociate(frdataset);
+		}
 		goto cleanup;
 
 	default:
+		/*
+		 * Disassociate for the next dns_resolver_createfetch call.
+		 */
+		if (dns_rdataset_isassociated(frdataset)) {
+			dns_rdataset_disassociate(frdataset);
+		}
+
 		/*
 		 * If the chain of resume_dslookup() invocations managed to
 		 * chop off enough labels from the original DS owner name to
@@ -7058,10 +7076,6 @@ resume_dslookup(void *arg) {
 cleanup:
 	dns_resolver_destroyfetch(&fetch);
 
-	if (dns_rdataset_isassociated(frdataset)) {
-		dns_rdataset_disassociate(frdataset);
-	}
-
 	if (result != ISC_R_SUCCESS) {
 		/* An error occurred, tear down whole fctx */
 		fctx_done_unref(fctx, result);