From: Jan Hak <jan.hak@nic.cz>
Date: Fri, 8 Jan 2021 13:00:17 +0000 (+0100)
Subject: zone-update: sanitize freed pointers to avoid possible double free
X-Git-Tag: v3.1.0~264^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7beeae41698e0ae0bc05ab79568637622cff5bce;p=thirdparty%2Fknot-dns.git

zone-update: sanitize freed pointers to avoid possible double free
---

diff --git a/src/knot/updates/zone-update.c b/src/knot/updates/zone-update.c
index b18aaac34d..2408bb6c87 100644
--- a/src/knot/updates/zone-update.c
+++ b/src/knot/updates/zone-update.c
@@ -244,6 +244,7 @@ int zone_update_from_contents(zone_update_t *update, zone_t *zone_without_conten
 		int ret = changeset_init(&update->change, zone_without_contents->name);
 		if (ret != KNOT_EOK) {
 			free(update->a_ctx);
+			update->a_ctx = NULL;
 			knot_sem_post(&update->zone->cow_lock);
 			return ret;
 		}
@@ -252,6 +253,7 @@ int zone_update_from_contents(zone_update_t *update, zone_t *zone_without_conten
 		if (update->change.soa_from == NULL) {
 			changeset_clear(&update->change);
 			free(update->a_ctx);
+			update->a_ctx = NULL;
 			knot_sem_post(&update->zone->cow_lock);
 			return KNOT_ENOMEM;
 		}
@@ -262,6 +264,7 @@ int zone_update_from_contents(zone_update_t *update, zone_t *zone_without_conten
 	if (ret != KNOT_EOK) {
 		changeset_clear(&update->change);
 		free(update->a_ctx);
+		update->a_ctx = NULL;
 		knot_sem_post(&update->zone->cow_lock);
 		return ret;
 	}