From: Evan Hunt <each@isc.org>
Date: Tue, 4 Jan 2022 20:08:43 +0000 (-0800)
Subject: Prevent a shutdown race in catz_create_chg_task()
X-Git-Tag: v9.17.22~12^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=973ac1d8912d8d885e9a002ffee4acbaf23e9c81;p=thirdparty%2Fbind9.git

Prevent a shutdown race in catz_create_chg_task()

If a catz event is scheduled while the task manager was being
shut down, task-exclusive mode is unavailable. This needs to be
handled as an error rather than triggering an assertion.
---

diff --git a/bin/named/server.c b/bin/named/server.c
index 8e27090da85..4e741cb3857 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -2902,11 +2902,16 @@ static isc_result_t
 catz_create_chg_task(dns_catz_entry_t *entry, dns_catz_zone_t *origin,
 		     dns_view_t *view, isc_taskmgr_t *taskmgr, void *udata,
 		     isc_eventtype_t type) {
-	catz_chgzone_event_t *event;
-	isc_task_t *task;
+	catz_chgzone_event_t *event = NULL;
+	isc_task_t *task = NULL;
 	isc_result_t result;
 	isc_taskaction_t action = NULL;
 
+	result = isc_taskmgr_excltask(taskmgr, &task);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
 	switch (type) {
 	case DNS_EVENT_CATZADDZONE:
 	case DNS_EVENT_CATZMODZONE:
@@ -2917,6 +2922,7 @@ catz_create_chg_task(dns_catz_entry_t *entry, dns_catz_zone_t *origin,
 		break;
 	default:
 		REQUIRE(0);
+		ISC_UNREACHABLE();
 	}
 
 	event = (catz_chgzone_event_t *)isc_event_allocate(
@@ -2927,13 +2933,11 @@ catz_create_chg_task(dns_catz_entry_t *entry, dns_catz_zone_t *origin,
 	event->origin = NULL;
 	event->view = NULL;
 	event->mod = (type == DNS_EVENT_CATZMODZONE);
+
 	dns_catz_entry_attach(entry, &event->entry);
 	dns_catz_zone_attach(origin, &event->origin);
 	dns_view_attach(view, &event->view);
 
-	task = NULL;
-	result = isc_taskmgr_excltask(taskmgr, &task);
-	REQUIRE(result == ISC_R_SUCCESS);
 	isc_task_send(task, ISC_EVENT_PTR(&event));
 	isc_task_detach(&task);