From 83c0ef88159fcae73fdbf8fe04d220c1878cce3e Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Mon, 7 Nov 2011 23:03:09 +0000
Subject: [PATCH] 3210.	[bug]		Canceling the oldest query due to
 recursive-client 			overload could trigger an assertion
 failure. [RT #26463]

---
 CHANGES            |  3 +++
 bin/named/client.c | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 5327909be7..95e045582f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3210.	[bug]		Canceling the oldest query due to recursive-client
+			overload could trigger an assertion failure. [RT #26463]
+
 3209.	[func]		Add "dnssec-lookaside 'no'".  [RT #24858]
 
 3208.	[bug]		'dig -y' handle unknown tsig alorithm better.
diff --git a/bin/named/client.c b/bin/named/client.c
index 374fdbaaff..d77e73bb5c 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: client.c,v 1.282 2011/11/03 21:14:22 each Exp $ */
+/* $Id: client.c,v 1.283 2011/11/07 23:03:09 each Exp $ */
 
 #include <config.h>
 
@@ -349,10 +349,16 @@ exit_check(ns_client_t *client) {
 		 * I/O cancel is complete.  Burn down all state
 		 * related to the current request.  Ensure that
 		 * the client is no longer on the recursing list.
+		 *
+		 * We need to check whether the client is still linked,
+		 * because it may already have been removed from the
+		 * recursing list by ns_client_killoldestquery()
 		 */
 		if (client->state == NS_CLIENTSTATE_RECURSING) {
 			LOCK(&manager->reclock);
-			ISC_LIST_UNLINK(manager->recursing, client, rlink);
+			if (ISC_LINK_LINKED(client, rlink))
+				ISC_LIST_UNLINK(manager->recursing,
+						client, rlink);
 			UNLOCK(&manager->reclock);
 		}
 		ns_client_endrequest(client);