From: Witold Kręcicki <wpk@isc.org>
Date: Sat, 31 Oct 2020 20:08:53 +0000 (+0100)
Subject: Fix improper closed connection handling in tcpdns.
X-Git-Tag: v9.17.7~29^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3ab3d90de039a3f086bba9c25792e42dd1b4a614;p=thirdparty%2Fbind9.git

Fix improper closed connection handling in tcpdns.

If dnslisten_readcb gets a read callback it needs to verify that the
outer socket wasn't closed in the meantime, and issue a CANCELED callback
if it was.
---

diff --git a/lib/isc/netmgr/tcpdns.c b/lib/isc/netmgr/tcpdns.c
index 255c44fe2c3..f5df92c1056 100644
--- a/lib/isc/netmgr/tcpdns.c
+++ b/lib/isc/netmgr/tcpdns.c
@@ -259,6 +259,11 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult,
 	REQUIRE(VALID_NMSOCK(dnssock));
 	REQUIRE(dnssock->tid == isc_nm_tid());
 	REQUIRE(VALID_NMHANDLE(handle));
+	if (eresult == ISC_R_SUCCESS &&
+	    (!isc__nmsocket_active(dnssock) || dnssock->outerhandle == NULL))
+	{
+		eresult = ISC_R_CANCELED;
+	}
 
 	if (region == NULL || eresult != ISC_R_SUCCESS) {
 		/* Connection closed */