upstream/bind9
1
0
Fork 0
mirror of https://github.com/isc-projects/bind9.git synced 2026-06-11 16:19:59 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

4558. [bug] Synthesised CNAME before matching DNAME was still

Browse source 
being cached when it should have been.  [RT #44318]

(cherry picked from commit 9f4bf43b79)
This commit is contained in:
Mark Andrews 2017-01-24 17:40:12 +11:00
parent c5eedfe91f
commit e63f8e9467
2 changed files with 26 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
CHANGES
View file

@ -1,3 +1,6 @@
4558. [bug] Synthesised CNAME before matching DNAME was still
being cached when it should have been. [RT #44318]
4557. [security] Combining dns64 and rpz can result in dereferencing
a NULL pointer (read). (CVE-2017-3135) [RT#44434]

35
lib/dns/resolver.c
View file

@ -6751,10 +6751,10 @@ answer_response(fetchctx_t *fctx) {
dns_name_t *name, *dname = NULL, *qname, tname, *ns_name;
dns_name_t *cname = NULL;
dns_rdataset_t *rdataset, *ns_rdataset;
isc_boolean_t done, external, chaining, aa, found, want_chaining;
isc_boolean_t done, external, aa, found, want_chaining;
isc_boolean_t have_answer, found_cname, found_dname, found_type;
isc_boolean_t wanted_chaining;
unsigned int aflag;
unsigned int aflag, chaining;
dns_rdatatype_t type;
dns_fixedname_t fdname, fqname;
dns_view_t *view;
@ -6772,9 +6772,9 @@ answer_response(fetchctx_t *fctx) {
found_cname = ISC_FALSE;
found_dname = ISC_FALSE;
found_type = ISC_FALSE;
chaining = ISC_FALSE;
have_answer = ISC_FALSE;
want_chaining = ISC_FALSE;
chaining = 0;
POST(want_chaining);
if ((message->flags & DNS_MESSAGEFLAG_AA) != 0)
aa = ISC_TRUE;
@ -6921,7 +6921,7 @@ answer_response(fetchctx_t *fctx) {
rdataset->attributes |=
DNS_RDATASETATTR_CACHE;
rdataset->trust = dns_trust_answer;
if (!chaining) {
if (chaining == 0) {
/*
* This data is "the" answer
* to our question only if
@ -6998,8 +6998,8 @@ answer_response(fetchctx_t *fctx) {
* cause us to ignore the signatures of
* CNAMEs.
*/
if (wanted_chaining)
chaining = ISC_TRUE;
if (wanted_chaining && chaining < 2U)
chaining++;
} else {
dns_rdataset_t *dnameset = NULL;
@ -7030,7 +7030,7 @@ answer_response(fetchctx_t *fctx) {
* If we're not chaining, then the DNAME and
* its signature should not be external.
*/
if (!chaining && external) {
if (chaining == 0 && external) {
char qbuf[DNS_NAME_FORMATSIZE];
char obuf[DNS_NAME_FORMATSIZE];
@ -7114,7 +7114,14 @@ answer_response(fetchctx_t *fctx) {
name->attributes |= DNS_NAMEATTR_CACHE;
rdataset->attributes |= DNS_RDATASETATTR_CACHE;
rdataset->trust = dns_trust_answer;
if (!chaining) {
/*
* If we are not chaining or the first CNAME
* is a synthesised CNAME before the DNAME.
*/
if ((chaining == 0) ||
(chaining == 1U &&
namereln == dns_namereln_commonancestor))
{
/*
* This data is "the" answer to
* our question only if we're
@ -7162,8 +7169,12 @@ answer_response(fetchctx_t *fctx) {
dnameset->attributes |=
DNS_RDATASETATTR_CHAINING;
}
if (wanted_chaining)
chaining = ISC_TRUE;
/*
* Ensure that we can't ever get chaining == 1
* above if we have processed a DNAME.
*/
if (wanted_chaining && chaining < 2U)
chaining += 2;
}
result = dns_message_nextname(message, DNS_SECTION_ANSWER);
}
@ -7188,7 +7199,7 @@ answer_response(fetchctx_t *fctx) {
/*
* Did chaining end before we got the final answer?
*/
if (chaining) {
if (chaining != 0) {
/*
* Yes. This may be a negative reply, so hand off
* authority section processing to the noanswer code.
@ -7237,7 +7248,7 @@ answer_response(fetchctx_t *fctx) {
DNS_NAMEATTR_CACHE;
rdataset->attributes |=
DNS_RDATASETATTR_CACHE;
if (aa && !chaining)
if (aa && chaining == 0)
rdataset->trust =
dns_trust_authauthority;
else