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gerrit.openbmc.org / mdmillerii / openbmc / 66859fe4b5a21319cfef9ec3e23334c6769bdd59 / . / yocto-poky / meta / recipes-connectivity / bind / bind / CVE-2016-1286_2.patch
blob: a31ea81f870bcea64bef0dc9511c406c983551f0 [file] [log] [blame]
From 7602be276a73a6eb5431c5acd9718e68a55e8b61 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Mon, 29 Feb 2016 07:16:48 +1100
Subject: [PATCH] Part 2 of: 4319. [security] Fix resolver assertion
failure due to improper DNAME handling when parsing
fetch reply messages. (CVE-2016-1286) [RT #41753]
(cherry picked from commit 2de89ee9de8c8da9dc153a754b02dcdbb7fe2374)
Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
---
lib/dns/resolver.c | 192 ++++++++++++++++++++++++++---------------------------
1 file changed, 93 insertions(+), 99 deletions(-)
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 70aba87..41e9df4 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -6074,14 +6074,11 @@ cname_target(dns_rdataset_t *rdataset, dns_name_t *tname) {
}
static inline isc_result_t
-dname_target(fetchctx_t *fctx, dns_rdataset_t *rdataset, dns_name_t *qname,
- dns_name_t *oname, dns_fixedname_t *fixeddname)
+dname_target(dns_rdataset_t *rdataset, dns_name_t *qname,
+ unsigned int nlabels, dns_fixedname_t *fixeddname)
{
isc_result_t result;
dns_rdata_t rdata = DNS_RDATA_INIT;
- unsigned int nlabels;
- int order;
- dns_namereln_t namereln;
dns_rdata_dname_t dname;
dns_fixedname_t prefix;
@@ -6096,21 +6093,6 @@ dname_target(fetchctx_t *fctx, dns_rdataset_t *rdataset, dns_name_t *qname,
if (result != ISC_R_SUCCESS)
return (result);
- /*
- * Get the prefix of qname.
- */
- namereln = dns_name_fullcompare(qname, oname, &order, &nlabels);
- if (namereln != dns_namereln_subdomain) {
- char qbuf[DNS_NAME_FORMATSIZE];
- char obuf[DNS_NAME_FORMATSIZE];
-
- dns_rdata_freestruct(&dname);
- dns_name_format(qname, qbuf, sizeof(qbuf));
- dns_name_format(oname, obuf, sizeof(obuf));
- log_formerr(fctx, "unrelated DNAME in answer: "
- "%s is not in %s", qbuf, obuf);
- return (DNS_R_FORMERR);
- }
dns_fixedname_init(&prefix);
dns_name_split(qname, nlabels, dns_fixedname_name(&prefix), NULL);
dns_fixedname_init(fixeddname);
@@ -6736,13 +6718,13 @@ static isc_result_t
answer_response(fetchctx_t *fctx) {
isc_result_t result;
dns_message_t *message;
- dns_name_t *name, *qname, tname, *ns_name;
+ dns_name_t *name, *dname, *qname, tname, *ns_name;
dns_rdataset_t *rdataset, *ns_rdataset;
isc_boolean_t done, external, chaining, aa, found, want_chaining;
isc_boolean_t have_answer, found_cname, found_type, wanted_chaining;
unsigned int aflag;
dns_rdatatype_t type;
- dns_fixedname_t dname, fqname;
+ dns_fixedname_t fdname, fqname;
dns_view_t *view;
FCTXTRACE("answer_response");
@@ -6770,10 +6752,15 @@ answer_response(fetchctx_t *fctx) {
view = fctx->res->view;
result = dns_message_firstname(message, DNS_SECTION_ANSWER);
while (!done && result == ISC_R_SUCCESS) {
+ dns_namereln_t namereln;
+ int order;
+ unsigned int nlabels;
+
name = NULL;
dns_message_currentname(message, DNS_SECTION_ANSWER, &name);
external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
- if (dns_name_equal(name, qname)) {
+ namereln = dns_name_fullcompare(qname, name, &order, &nlabels);
+ if (namereln == dns_namereln_equal) {
wanted_chaining = ISC_FALSE;
for (rdataset = ISC_LIST_HEAD(name->list);
rdataset != NULL;
@@ -6898,10 +6885,11 @@ answer_response(fetchctx_t *fctx) {
*/
INSIST(!external);
if (aflag ==
- DNS_RDATASETATTR_ANSWER)
+ DNS_RDATASETATTR_ANSWER) {
have_answer = ISC_TRUE;
- name->attributes |=
- DNS_NAMEATTR_ANSWER;
+ name->attributes |=
+ DNS_NAMEATTR_ANSWER;
+ }
rdataset->attributes |= aflag;
if (aa)
rdataset->trust =
@@ -6956,6 +6944,8 @@ answer_response(fetchctx_t *fctx) {
if (wanted_chaining)
chaining = ISC_TRUE;
} else {
+ dns_rdataset_t *dnameset = NULL;
+
/*
* Look for a DNAME (or its SIG). Anything else is
* ignored.
@@ -6963,10 +6953,8 @@ answer_response(fetchctx_t *fctx) {
wanted_chaining = ISC_FALSE;
for (rdataset = ISC_LIST_HEAD(name->list);
rdataset != NULL;
- rdataset = ISC_LIST_NEXT(rdataset, link)) {
- isc_boolean_t found_dname = ISC_FALSE;
- dns_name_t *dname_name;
-
+ rdataset = ISC_LIST_NEXT(rdataset, link))
+ {
/*
* Only pass DNAME or RRSIG(DNAME).
*/
@@ -6980,20 +6968,41 @@ answer_response(fetchctx_t *fctx) {
* its signature should not be external.
*/
if (!chaining && external) {
- log_formerr(fctx, "external DNAME");
+ char qbuf[DNS_NAME_FORMATSIZE];
+ char obuf[DNS_NAME_FORMATSIZE];
+
+ dns_name_format(name, qbuf,
+ sizeof(qbuf));
+ dns_name_format(&fctx->domain, obuf,
+ sizeof(obuf));
+ log_formerr(fctx, "external DNAME or "
+ "RRSIG covering DNAME "
+ "in answer: %s is "
+ "not in %s", qbuf, obuf);
+ return (DNS_R_FORMERR);
+ }
+
+ if (namereln != dns_namereln_subdomain) {
+ char qbuf[DNS_NAME_FORMATSIZE];
+ char obuf[DNS_NAME_FORMATSIZE];
+
+ dns_name_format(qname, qbuf,
+ sizeof(qbuf));
+ dns_name_format(name, obuf,
+ sizeof(obuf));
+ log_formerr(fctx, "unrelated DNAME "
+ "in answer: %s is "
+ "not in %s", qbuf, obuf);
return (DNS_R_FORMERR);
}
- found = ISC_FALSE;
aflag = 0;
if (rdataset->type == dns_rdatatype_dname) {
- found = ISC_TRUE;
want_chaining = ISC_TRUE;
POST(want_chaining);
aflag = DNS_RDATASETATTR_ANSWER;
- result = dname_target(fctx, rdataset,
- qname, name,
- &dname);
+ result = dname_target(rdataset, qname,
+ nlabels, &fdname);
if (result == ISC_R_NOSPACE) {
/*
* We can't construct the
@@ -7005,14 +7014,12 @@ answer_response(fetchctx_t *fctx) {
} else if (result != ISC_R_SUCCESS)
return (result);
else
- found_dname = ISC_TRUE;
+ dnameset = rdataset;
- dname_name = dns_fixedname_name(&dname);
+ dname = dns_fixedname_name(&fdname);
if (!is_answertarget_allowed(view,
- qname,
- rdataset->type,
- dname_name,
- &fctx->domain)) {
+ qname, rdataset->type,
+ dname, &fctx->domain)) {
return (DNS_R_SERVFAIL);
}
} else {
@@ -7020,73 +7027,60 @@ answer_response(fetchctx_t *fctx) {
* We've found a signature that
* covers the DNAME.
*/
- found = ISC_TRUE;
aflag = DNS_RDATASETATTR_ANSWERSIG;
}
- if (found) {
+ /*
+ * We've found an answer to our
+ * question.
+ */
+ name->attributes |= DNS_NAMEATTR_CACHE;
+ rdataset->attributes |= DNS_RDATASETATTR_CACHE;
+ rdataset->trust = dns_trust_answer;
+ if (!chaining) {
/*
- * We've found an answer to our
- * question.
+ * This data is "the" answer to
+ * our question only if we're
+ * not chaining.
*/
- name->attributes |=
- DNS_NAMEATTR_CACHE;
- rdataset->attributes |=
- DNS_RDATASETATTR_CACHE;
- rdataset->trust = dns_trust_answer;
- if (!chaining) {
- /*
- * This data is "the" answer
- * to our question only if
- * we're not chaining.
- */
- INSIST(!external);
- if (aflag ==
- DNS_RDATASETATTR_ANSWER)
- have_answer = ISC_TRUE;
+ INSIST(!external);
+ if (aflag == DNS_RDATASETATTR_ANSWER) {
+ have_answer = ISC_TRUE;
name->attributes |=
DNS_NAMEATTR_ANSWER;
- rdataset->attributes |= aflag;
- if (aa)
- rdataset->trust =
- dns_trust_authanswer;
- } else if (external) {
- rdataset->attributes |=
- DNS_RDATASETATTR_EXTERNAL;
- }
-
- /*
- * DNAME chaining.
- */
- if (found_dname) {
- /*
- * Copy the dname into the
- * qname fixed name.
- *
- * Although we check for
- * failure of the copy
- * operation, in practice it
- * should never fail since
- * we already know that the
- * result fits in a fixedname.
- */
- dns_fixedname_init(&fqname);
- result = dns_name_copy(
- dns_fixedname_name(&dname),
- dns_fixedname_name(&fqname),
- NULL);
- if (result != ISC_R_SUCCESS)
- return (result);
- wanted_chaining = ISC_TRUE;
- name->attributes |=
- DNS_NAMEATTR_CHAINING;
- rdataset->attributes |=
- DNS_RDATASETATTR_CHAINING;
- qname = dns_fixedname_name(
- &fqname);
}
+ rdataset->attributes |= aflag;
+ if (aa)
+ rdataset->trust =
+ dns_trust_authanswer;
+ } else if (external) {
+ rdataset->attributes |=
+ DNS_RDATASETATTR_EXTERNAL;
}
}
+
+ /*
+ * DNAME chaining.
+ */
+ if (dnameset != NULL) {
+ /*
+ * Copy the dname into the qname fixed name.
+ *
+ * Although we check for failure of the copy
+ * operation, in practice it should never fail
+ * since we already know that the result fits
+ * in a fixedname.
+ */
+ dns_fixedname_init(&fqname);
+ qname = dns_fixedname_name(&fqname);
+ result = dns_name_copy(dname, qname, NULL);
+ if (result != ISC_R_SUCCESS)
+ return (result);
+ wanted_chaining = ISC_TRUE;
+ name->attributes |= DNS_NAMEATTR_CHAINING;
+ dnameset->attributes |=
+ DNS_RDATASETATTR_CHAINING;
+ }
if (wanted_chaining)
chaining = ISC_TRUE;
}
--
1.9.1