changelog-9.20.24.rst revision 1.1 1 .. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
2 ..
3 .. SPDX-License-Identifier: MPL-2.0
4 ..
5 .. This Source Code Form is subject to the terms of the Mozilla Public
6 .. License, v. 2.0. If a copy of the MPL was not distributed with this
7 .. file, you can obtain one at https://mozilla.org/MPL/2.0/.
8 ..
9 .. See the COPYRIGHT file distributed with this work for additional
10 .. information regarding copyright ownership.
11
12 BIND 9.20.24
13 ------------
14
15 Security Fixes
16 ~~~~~~~~~~~~~~
17
18 - Fix DNS64 owner case after DNAME restart. ``4de2229364``
19
20 When BIND 9 is configured to use DNS64 and encounters a DNAME
21 redirect, it could end up using freed memory for the DNS response
22 owner name. This caused the response to contain corrupted data. This
23 fix ensures the correct owner name is used when constructing the
24 synthesized response after a DNAME redirect.
25
26 ISC thanks Qifan Zhang of Palo Alto Networks for reporting the issue.
27 :gl:`#5934`
28
29 New Features
30 ~~~~~~~~~~~~
31
32 - Enable PR-Agent reviews on merge requests. ``46e4c236a3``
33
34 Adds a CI job that runs PR-Agent against each merge request opened
35 from the canonical repository, posting an automated review and
36 code-improvement suggestions as MR comments. The job is gated to
37 same-project source branches so the OpenAI key and personal access
38 token are not exposed to fork pipelines. :gl:`!12034`
39
40 Removed Features
41 ~~~~~~~~~~~~~~~~
42
43 - Remove ineffective TCP fallback after repeated UDP timeouts.
44 ``eb13adcb47``
45
46 When an authoritative server failed to respond to two consecutive UDP
47 queries, named marked the next retry as TCP but still sent it over
48 UDP, producing misleading dnstap records. The ineffective retry path
49 has been removed; a corrected TCP fallback will be restored in future
50 BIND 9 versions. :gl:`#5529` :gl:`!12049`
51
52 - Remove useless PR-Agent jobs. ``8851b279d0``
53
54 The experiment was a failure, the PR-Agent doesn't send a full context
55 to the AI Agents and the results are abysmal because of that.
56 :gl:`!12120`
57
58 Feature Changes
59 ~~~~~~~~~~~~~~~
60
61 - Fall back to TCP on a UDP response with a mismatched query id.
62 ``b2367aaea2``
63
64 BIND used to wait silently for the correct DNS message id on a UDP
65 fetch even after receiving a response from the expected server with
66 the wrong id, leaving room for off-path spoofing attempts to keep
67 guessing within that window. The resolver now retries the fetch over
68 TCP on the first such response, and a new MismatchTCP statistics
69 counter tracks how often the fallback fires. :gl:`#5449` :gl:`!12025`
70
71 - Limit the number of glue records cached from a referral.
72 ``eb401f6b92``
73
74 When a delegation response contained many glue addresses per listed
75 nameserver, all of them were cached without a per-nameserver bound,
76 inflating resolver cache memory beyond what resolution could ever use.
77 The cache now keeps at most 20 IPv4 and 20 IPv6 glue addresses per
78 nameserver from a delegation. :gl:`#5701` :gl:`!11972`
79
80 - Fix a resolver stall on a CNAME response to a DS query. ``1407f48670``
81
82 A validating resolver could stall for about twelve seconds and then
83 return SERVFAIL when an authoritative server answered a DS query with
84 a CNAME. Such responses are now rejected promptly, so the query fails
85 fast instead of hanging. :gl:`#5878` :gl:`!12147`
86
87 - Named could crash on concurrent TKEY DELETE for the same key.
88 ``dd02abde67``
89
90 On a server configured with tkey-gssapi-keytab (or
91 tkey-gssapi-credential), an authenticated peer could crash named by
92 sending two TKEY DELETE requests for the same dynamic key in rapid
93 succession. This has been fixed. :gl:`#6001` :gl:`!12042`
94
95 Bug Fixes
96 ~~~~~~~~~
97
98 - The resolver now removes other RRsets at the same name when caching a
99 CNAME. ``1547447491``
100
101 When an RRset is in stale cache, and the authoritative server changes
102 the record type to CNAME, the resolver fails to refresh the stale
103 cache. This has been fixed. :gl:`#5302` :gl:`!12040`
104
105 - Fix nxdomain-redirect combined with dns64. ``95274e9455``
106
107 When a resolver was configured with both `nxdomain-redirect` and
108 `dns64` in the same view, an AAAA query for a nonexistent name could
109 abort `named`. The combination failed whenever the redirect zone held
110 A records but no AAAA records. The server now serves the empty AAAA
111 response from the redirect zone as-is, instead of attempting DNS64
112 synthesis on top of it. :gl:`#5789` :gl:`!12123`
113
114 - Clear REDIRECT flag when it isn't needed. ``86bb27060c``
115
116 When `nxdomain-redirect` is in use, and a recursive query is used to
117 get the redirected answer, a flag is set to distinguish it from a
118 normal recursive response. Previously, that flag was left set
119 afterward, which could trigger an assertion if a normal recursive
120 query was sent later on behalf of the same client: for example,
121 because the `filter-aaaa` plugin was in use. This has been fixed.
122 :gl:`#5936` :gl:`!12076`
123
124 - Fix data race during rndc dumpdb or zone load. ``947e5c7983``
125
126 'rndc dumpdb' against a server with zones, and async zone load, had a
127 timing window where the operation's completion could fire before the
128 server had finished registering the operation, occasionally leading to
129 a possible crash. The completion is now delivered after the
130 registration is in place. :gl:`#5952` :gl:`!12021`
131
132 - Bound memory use during incoming zone transfers. ``5d7f241fdf``
133
134 During an incoming zone transfer, an optimization could let the batch
135 of pending records grow without bound for a large zone, raising memory
136 usage. It gave no measurable performance benefit, so it has been
137 removed. :gl:`#5958` :gl:`!12142`
138
139 - Disable output escaping in bind9.xsl. ``b514e663eb``
140
141 The statistics charts where not displaying on some browsers. This has
142 been fixed. :gl:`#5990` :gl:`!12019`
143
144 - Fix crash on badly configured secondary signer. ``edc1ef084f``
145
146 A badly configured secondary signer that was missing the 'file' entry
147 caused the server to crash, rather than to reject the configuration.
148 This has been fixed. :gl:`#5993` :gl:`!12112`
149
150 - Avoid named assertion failure during parent-NS lookups when none
151 exist. ``5c0c4786dd``
152
153 Configuring the root zone as a signed primary with parental agents (or
154 with notify-on-cds-changes) caused named to exit on an internal
155 assertion as soon as the DS-publication machinery tried to look up the
156 parent NS RRset the root has no parent. The lookup is now
157 short-circuited cleanly.
158
159 Similar, a zone with no NS records in the parent caused named to exit
160 in the same way. :gl:`#5910` :gl:`#5996` :gl:`!12053`
161
162 - Reject RRSIG records covering meta-types. ``7517e39504``
163
164 A recursive resolver could accept and cache an RRSIG record whose
165 Type-Covered field names a meta-type (ANY, AXFR, IXFR, MAILA, MAILB),
166 even though no real RRset of those types ever exists. Such records are
167 now rejected by the DNS message parser. :gl:`#6002` :gl:`!12051`
168
169 - Validate nsec3hash arguments instead of relying on atoi()
170 ``a59080c053``
171
172 The nsec3hash tool parsed its algorithm, flags, and iterations
173 arguments with atoi(), then range-checked the result. For values that
174 overflow int during digit-by-digit accumulation, atoi() is undefined;
175 in practice on musl libc the modular wrap leaves n == 0, which
176 silently passes the "iterations > 0xffffU" check. On Alpine Linux this
177 made nsec3hash succeed with iterations treated as 0 for inputs like
178 4294967296 (2^32).
179
180 The latent bug only surfaced when the recent image rebuild pulled in
181 Hypothesis 6.152.9 (2026-05-19), which unified the distribution used
182 for bounded and unbounded integers() strategies. The new smoother
183 distribution explores the 2^32 boundary on unbounded ranges like
184 integers(min_value=65536); earlier versions did not reach there, so
185 test_nsec3hash_too_many_iterations only started failing on Alpine
186 after the image refresh.
187
188 Replace the three atoi() calls with isc_parse_uint8 /
189 isc_parse_uint16, which uniformly reject overflow, trailing garbage,
190 leading sign, and non-numeric input across libc implementations. As a
191 side effect, error messages now include the offending argument and a
192 specific reason ("out of range" vs "not a valid number").
193
194 Assisted-by: Claude:claude-opus-4-7 :gl:`#6013` :gl:`!12074`
195
196 - Fix wrong variable in named_server_sync() log message. ``09f9889ef6``
197
198 named_server_sync() logged isc_result_totext(result) but returns
199 tresult. The loop accumulates errors into tresult, so result only
200 holds the last iteration's value. If the last view succeeded but an
201 earlier one failed, the log would incorrectly say "success".
202 :gl:`!12156`
203
204 - Refine resolver fetch loop detection. ``787faa02a7``
205
206 The resolver's fetch loop detection now triggers only when a new fetch
207 would join an already in-flight fetch that is also one of its own
208 ancestors, which is the actual loop condition. Previously the check
209 ran against the original request before the fetch was set up.
210 :gl:`!12146`
211
212
213