prevent a reference leak from the ns_query_done hooks

if the NS_QUERY_DONE_BEGIN or NS_QUERY_DONE_SEND hook is
used in a plugin and returns NS_HOOK_RETURN, some of the
cleanup in ns_query_done() can be skipped over, leading
to reference leaks that can cause named to hang on shut
down.

this has been addressed by adding more housekeeping
code after the cleanup: tag in ns_query_done().
This commit is contained in:
Evan Hunt 2025-01-21 17:57:00 -08:00
parent 26f8ee7229
commit c2e4358267
2 changed files with 18 additions and 4 deletions

View file

@ -212,6 +212,7 @@ struct query_ctx {
ns_client_t *client; /* client object */
bool detach_client; /* client needs detaching */
bool async; /* asynchronous hook running */
dns_fetchresponse_t *fresp; /* recursion response */

View file

@ -5070,6 +5070,9 @@ qctx_clean(query_ctx_t *qctx) {
if (qctx->db != NULL && qctx->node != NULL) {
dns_db_detachnode(qctx->db, &qctx->node);
}
if (qctx->client != NULL && qctx->client->query.gluedb != NULL) {
dns_db_detach(&qctx->client->query.gluedb);
}
}
/*%
@ -6728,6 +6731,9 @@ ns_query_hookasync(query_ctx_t *qctx, ns_query_starthookasync_t runasync,
goto cleanup_and_detach_from_quota;
}
/* Record that an asynchronous copy of the qctx has been started */
qctx->async = true;
/*
* Typically the runasync() function will trigger recursion, but
* there is no need to set NS_QUERYATTR_RECURSING. The calling hook
@ -11372,10 +11378,6 @@ ns_query_done(query_ctx_t *qctx) {
qctx_clean(qctx);
qctx_freedata(qctx);
if (qctx->client->query.gluedb != NULL) {
dns_db_detach(&qctx->client->query.gluedb);
}
/*
* Clear the AA bit if we're not authoritative.
*/
@ -11513,6 +11515,17 @@ ns_query_done(query_ctx_t *qctx) {
return qctx->result;
cleanup:
/*
* We'd only get here if one of the hooks above
* (NS_QUERY_DONE_BEGIN or NS_QUERY_DONE_SEND) returned
* NS_HOOK_RETURN. Some housekeeping may be needed.
*/
qctx_clean(qctx);
qctx_freedata(qctx);
if (!qctx->async) {
qctx->detach_client = true;
query_error(qctx->client, DNS_R_SERVFAIL, __LINE__);
}
return result;
}