From: Aram Sargsyan <aram@isc.org>
Date: Wed, 27 Apr 2022 12:29:50 +0000 (+0000)
Subject: Handle ISC_R_SUCCESS on a deactivated response in udp_recv()
X-Git-Tag: v9.19.1~42^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e3a88862c0e0a7b9a58727b321ff1424e003fc4d;p=thirdparty%2Fbind9.git

Handle ISC_R_SUCCESS on a deactivated response in udp_recv()

There is a possibility for `udp_recv()` to be called with `eresult`
being `ISC_R_SUCCESS`, but nevertheless with already deactivated `resp`,
which can happen when the request has been canceled in the meantime.
---

diff --git a/lib/dns/dispatch.c b/lib/dns/dispatch.c
index 74df922623e..d4de0f74049 100644
--- a/lib/dns/dispatch.c
+++ b/lib/dns/dispatch.c
@@ -491,6 +491,8 @@ udp_recv(isc_nmhandle_t *handle, isc_result_t eresult, isc_region_t *region,
 	 */
 	if (ISC_LINK_LINKED(resp, alink)) {
 		response = resp->response;
+	} else if (eresult == ISC_R_SUCCESS) {
+		eresult = ISC_R_CANCELED;
 	}
 
 	if (eresult != ISC_R_SUCCESS) {
@@ -503,8 +505,6 @@ udp_recv(isc_nmhandle_t *handle, isc_result_t eresult, isc_region_t *region,
 		goto done;
 	}
 
-	INSIST(ISC_LINK_LINKED(resp, alink));
-
 	peer = isc_nmhandle_peeraddr(handle);
 	isc_netaddr_fromsockaddr(&netaddr, &peer);