From: JINMEI Tatuya <jtatuya@infoblox.com>
Date: Sat, 12 Dec 2020 05:44:54 +0000 (-0800)
Subject: detach fetchhandle before resume query processing
X-Git-Tag: v9.17.9~11^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d520f01c7bf85165ec7410bb2c83bab2b49789f0;p=thirdparty%2Fbind9.git

detach fetchhandle before resume query processing

otherwise, another hook async event or DNS recursion would
trigger an assertion failure.
---

diff --git a/lib/ns/query.c b/lib/ns/query.c
index 10a08ce4e00..bbaf1c91b15 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -6349,6 +6349,15 @@ query_hookresume(isc_task_t *task, isc_event_t *event) {
 		ISC_LIST_UNLINK(client->manager->recursing, client, rlink);
 	}
 	UNLOCK(&client->manager->reclock);
+
+	/*
+	 * This event is running under a client task, so it's safe to detach
+	 * the fetch handle.  And it should be done before resuming query
+	 * processing below, since that may trigger another recursion or
+	 * asynchronous hook event.
+	 */
+	isc_nmhandle_detach(&client->fetchhandle);
+
 	client->state = NS_CLIENTSTATE_WORKING;
 
 	if (canceled) {
@@ -6450,7 +6459,6 @@ query_hookresume(isc_task_t *task, isc_event_t *event) {
 	qctx_destroy(qctx);
 	isc_mem_put(client->mctx, qctx, sizeof(*qctx));
 	isc_event_free(&event);
-	isc_nmhandle_detach(&client->fetchhandle);
 }
 
 isc_result_t
diff --git a/lib/ns/tests/query_test.c b/lib/ns/tests/query_test.c
index 0f6a598c5be..d5943bc7751 100644
--- a/lib/ns/tests/query_test.c
+++ b/lib/ns/tests/query_test.c
@@ -717,7 +717,12 @@ hook_recurse_common(void *arg, void *data, isc_result_t *resultp,
 			asdata->async = true;
 		}
 	} else {
-		/* Resume from the completion of recursion */
+		/*
+		 * Resume from the completion of async event.
+		 * fetchhandle should have been detached so that we can start
+		 * another async event or DNS recursive resolution.
+		 */
+		INSIST(qctx->client->fetchhandle == NULL);
 		asdata->async = false;
 		switch (hookpoint) {
 		case NS_QUERY_GOT_ANSWER_BEGIN: