From: Ondřej Surý <ondrej@isc.org>
Date: Wed, 9 Nov 2022 17:04:23 +0000 (+0100)
Subject: Don't use view->resolver directly when priming in dns_view_find()
X-Git-Tag: v9.19.8~64^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a8ba2403254ea120f31f849ee7f0cb2f996e6c2a;p=thirdparty%2Fbind9.git

Don't use view->resolver directly when priming in dns_view_find()

When starting priming from dns_view_find(), the dns_view shutdown could
be initiated by different thread, detaching from the resolver.  Use
dns_view_getresolver() to attach to the resolver under view->lock, so we
don't try to call dns_resolver_prime() with NULL pointer.

There are more accesses to view->resolver, (and also view->adb and
view->requestmgr that suffer from the same problem) in the dns_view
module, but they are all done in exclusive mode or under a view->lock.
---

diff --git a/lib/dns/view.c b/lib/dns/view.c
index 38fb06a6656..e2cd0c1577b 100644
--- a/lib/dns/view.c
+++ b/lib/dns/view.c
@@ -1037,9 +1037,14 @@ db_find:
 			 * We just used a hint.  Let the resolver know it
 			 * should consider priming.
 			 */
-			dns_resolver_prime(view->resolver);
-			dns_db_attach(view->hints, &db);
-			result = DNS_R_HINT;
+			dns_resolver_t *res = NULL;
+			result = dns_view_getresolver(view, &res);
+			if (result == ISC_R_SUCCESS) {
+				dns_resolver_prime(res);
+				dns_db_attach(view->hints, &db);
+				dns_resolver_detach(&res);
+				result = DNS_R_HINT;
+			}
 		} else if (result == DNS_R_NXRRSET) {
 			dns_db_attach(view->hints, &db);
 			result = DNS_R_HINTNXRRSET;