From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Thu, 4 May 2017 22:15:56 +0000 (-0400)
Subject: Fix potential NULL ptr deref in fr_dlist_insert_head
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1df8967cbbfeaa305f425e44bd4859304e5e1849;p=thirdparty%2Ffreeradius-server.git

Fix potential NULL ptr deref in fr_dlist_insert_head
---

diff --git a/src/lib/io/time.h b/src/lib/io/time.h
index a8d04082be8..05431fb785e 100644
--- a/src/lib/io/time.h
+++ b/src/lib/io/time.h
@@ -86,7 +86,7 @@ static inline void fr_dlist_insert_head(fr_dlist_t *head, fr_dlist_t *entry)
 {
 	entry->prev = head;
 	entry->next = head->next;
-	head->next->prev = entry;
+	if (head->next) head->next->prev = entry; /* Head may be the only node in the list */
 	head->next = entry;
 }