From: Paul Selkirk <pselkirk@isc.org>
Date: Thu, 16 Jul 2009 19:48:45 +0000 (+0000)
Subject: add a null check to avoid primary crash on contact with secondary [rt19705]
X-Git-Tag: v4_2_0a1~59
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d453265fd2286c25d4db73639c38d477efa4a1dc;p=thirdparty%2Fdhcp.git

add a null check to avoid primary crash on contact with secondary [rt19705]
---

diff --git a/RELNOTES b/RELNOTES
index 2c861576f..476c86218 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -164,6 +164,10 @@ work on other platforms. Please report any problems and suggested fixes to
   supported.  Note that, similarly to 3.0.x, for by-code lookups only the
   last option definition is used.
 
+- Fixed a bug where a time difference of greater than 60 seconds between a
+  failover pair could cause the primary to crash on contact with the
+  secondary.  Thanks to a patch from Steinar Haug.
+
 			Changes since 4.1.0b1
 
 - A missing "else" in dhcrelay.c could have caused an interface not to
diff --git a/server/failover.c b/server/failover.c
index 795f896a6..3bcfc23c5 100644
--- a/server/failover.c
+++ b/server/failover.c
@@ -597,7 +597,8 @@ isc_result_t dhcp_failover_link_signal (omapi_object_t *h,
 		omapi_signal ((omapi_object_t *)link -> state_object,
 			      "message", link);
 		link -> state = dhcp_flink_message_length_wait;
-		failover_message_dereference (&link -> imsg, MDL);
+		if (link -> imsg)
+			failover_message_dereference (&link -> imsg, MDL);
 		/* XXX This is dangerous because we could get into a tight
 		   XXX loop reading input without servicing any other stuff.
 		   XXX There needs to be a way to relinquish control but