Prepare release notes for BIND 9.20.20

doc/arm/notes.rst

@@ -45,6 +45,7 @@ The list of known issues affecting the latest version in the 9.20 branch can be
 found at
 https://gitlab.isc.org/isc-projects/bind9/-/wikis/Known-Issues-in-BIND-9.20
 
+.. include:: ../notes/notes-9.20.20.rst
 .. include:: ../notes/notes-9.20.19.rst
 .. include:: ../notes/notes-9.20.18.rst
 .. include:: ../notes/notes-9.20.17.rst

doc/notes/notes-9.20.20.rst

@@ -0,0 +1,116 @@
+.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+..
+.. SPDX-License-Identifier: MPL-2.0
+..
+.. This Source Code Form is subject to the terms of the Mozilla Public
+.. License, v. 2.0.  If a copy of the MPL was not distributed with this
+.. file, you can obtain one at https://mozilla.org/MPL/2.0/.
+..
+.. See the COPYRIGHT file distributed with this work for additional
+.. information regarding copyright ownership.
+
+Notes for BIND 9.20.20
+----------------------
+
+Feature Changes
+~~~~~~~~~~~~~~~
+
+- Record query time for all dnstap responses.
+
+  Not all DNS responses had the query time set in their corresponding
+  dnstap messages. This has been fixed. :gl:`#3695`
+
+- Optimize the TCP source port selection on Linux.
+
+  Enable a socket option on the outgoing TCP sockets to allow faster
+  selection of the source <address,port> tuple for different destination
+  <address,port> tuples when nearing over 70-80% of the source port
+  utilization.
+
+Bug Fixes
+~~~~~~~~~
+
+- Fix errors when retrying over TCP in notify_send_toaddr.
+
+  If the source address is not available do not attempt to retry over
+  TCP otherwise clear the TSIG key from the message prior to retrying.
+  :gl:`#5457`
+
+- Fetch loop detection improvements.
+
+  Fixes a case where an in-domain NS with an expired glue would fail to
+  resolve.
+
+  Let's consider the following parent-side delegation (both for
+  `foo.example.` and `dnshost.example.`
+
+  ``` foo.example.            3600    NS      ns.dnshost.example.
+  dnshost.example.        3600    NS      ns.dnshost.example.
+  ns.dnshost.example.     3600    A       1.2.3.4 ```      Then the
+  child-side of `dnshost.example.`:
+
+  ```     dnshost.example.        300     NS      ns.dnshost.example.
+  ns.dnshost.example.     300     A       1.2.3.4 ```      And then the
+  child-side of `foo.example.`:
+
+  ``` foo.example             3600    NS      ns.dnshost.example.
+  a.foo.example           300     A       5.6.7.8 ```
+
+  While there is a zone misconfiguration (the TTL of the delegation and
+  glue doesn't match in the parent and the child), it is possible to
+  resolve `a.foo.example` on a cold-cache resolver. However, after the
+  `ns.dnshost.example.` glue expires, the resolution would have failed
+  with a "fetch loop detected" error. This is now fixed. :gl:`#5588`
+
+- Remove deterministic selection of nameserver.
+
+  When selecting nameserver addresses to be looked up we where always
+  selecting them in dnssec name order from the start of the nameserver
+  rrset.  This could lead to resolution failure despite there being
+  address that could be resolved for the other names.  Use a random
+  starting point when selecting which names to lookup. :gl:`#5695`
+  :gl:`#5745`
+
+- DNSTAP wasn't logging forwarded queries correctly.
+
+  :gl:`#5724`
+
+- Fix read UAF in BIND9 dns_client_resolve() via DNAME Response.
+
+  An attacker controlling a malicious DNS server returns a DNAME record,
+  and the we stores a pointer to resp->foundname, frees the response
+  structure, then uses the dangling pointer in dns_name_fullcompare()
+  possibly causing invalid match.  Only the `delv`is affected.  This has
+  been fixed. :gl:`#5728`
+
+- Clear serve-stale flags when following the CNAME chains.
+
+  A stale answer could have been served in case of multiple upstream
+  failures when following the CNAME chains.  This has been fixed.
+  :gl:`#5751`
+
+- Fail DNSKEY validation when supported but invalid DS is found.
+
+  A regression was introduced when adding the EDE code for unsupported
+  DNSKEY and DS algorithms.  When the parent has both supported and
+  unsupported algorithm in the DS record, the validator would treat the
+  supported DS algorithm as insecure when validating DNSKEY records
+  instead of BOGUS.  This has not security impact as the rest of the
+  child zone correctly ends with BOGUS status, but it is incorrect and
+  thus the regression has been fixed. :gl:`#5757`
+
+- Importing invalid SKR file might corrupt stack memory.
+
+  If an BIND 9 administrator imports an invalid SKR file, local stack in
+  the import function might overflow.  This could lead to a memory
+  corruption on the stack and ultimately server crash. This has been
+  fixed.
+
+  ISC would like to thank mcsky23 for bringing this bug to our
+  attention. :gl:`#5758`
+
+- Do not update the case on unchanged rdatasets.
+
+  Fix assertion failure on unchanged rdataset during IXFR. :gl:`#5759`
+
+