BUG/MAJOR: dns: tcp session can remain attached to a list after a free
Using tcp, after a session release and free, the session can remain
attached to the list of sessions with a response message waiting for
a commit (ds->waiter). This results to a use after free of this
session.
Also, on some error path and after free, a session could remain attached
to the lists of available idle/free sessions (ds->list).
This patch ensure to remove the session from those external lists
before a free.
This patch should be backported to all version including
the dns over tcp (2.4)
diff --git a/src/dns.c b/src/dns.c
index fa6f2b9..433b554 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -758,6 +758,13 @@
dns_queries_flush(ds);
+ /* Ensure to remove this session from external lists
+ * Note: we are under the lock of dns_stream_server
+ * which own the heads of those lists.
+ */
+ LIST_DEL_INIT(&ds->waiter);
+ LIST_DEL_INIT(&ds->list);
+
ds->dss->cur_conns--;
/* Note: this is useless to update
* max_active_conns here because