From: Artem Boldariev <artem@boldariev.com>
Date: Fri, 2 Dec 2022 08:41:28 +0000 (+0200)
Subject: DoH: Avoid accessing non-atomic listener socket flags when accepting
X-Git-Tag: v9.19.8~22^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8b7e1235282a9e74efdb031920861381330e69ef;p=thirdparty%2Fbind9.git

DoH: Avoid accessing non-atomic listener socket flags when accepting

This commit ensures that the non-atomic flags inside a DoH listener
socket object (and associated worker) are accessed when doing accept
for a connection only from within the context of the dedicated thread,
but not other worker threads.

The purpose of this commit is to avoid TSAN errors during
isc__nmsocket_closing() calls. It is a continuation of
4b5559cd8f41e67bf03e92d9d0338dee9d549b48.
---

diff --git a/lib/isc/netmgr/http.c b/lib/isc/netmgr/http.c
index bd4a02ed682..7b1d6f7ece6 100644
--- a/lib/isc/netmgr/http.c
+++ b/lib/isc/netmgr/http.c
@@ -2459,7 +2459,9 @@ httplisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
 	 * function gets invoked, so we need to do extra sanity checks to
 	 * detect this case.
 	 */
-	if (isc__nmsocket_closing(handle->sock) || httpserver == NULL) {
+	if (isc__nm_closing(handle->sock->worker)) {
+		return (ISC_R_SHUTTINGDOWN);
+	} else if (isc__nmsocket_closing(handle->sock) || httpserver == NULL) {
 		return (ISC_R_CANCELED);
 	}
 
@@ -2471,9 +2473,7 @@ httplisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
 	REQUIRE(VALID_NMSOCK(httplistensock));
 	INSIST(httplistensock == httpserver);
 
-	if (isc__nmsocket_closing(httplistensock) ||
-	    !atomic_load(&httplistensock->listening))
-	{
+	if (atomic_load(&httplistensock->closing)) {
 		return (ISC_R_CANCELED);
 	}