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fix CVE-2020-10700 and CVE-2020-10704

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This commit is contained in:
sherlock2010 2020-05-20 16:57:28 +08:00
parent b406be5258
commit 7cef557ed7
9 changed files with 1451 additions and 1 deletions
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222
CVE-2020-10700-1.patch Normal file
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@ -0,0 +1,222 @@
From 0e77fa7747d789bd8c9256373498a352251f6877 Mon Sep 17 00:00:00 2001
From: Andrew Bartlett <abartlet@samba.org>
Date: Mon, 30 Mar 2020 09:44:20 +0000
Subject: [PATCH 1/4] CVE-2020-10700: dsdb: Add test for ASQ and ASQ in
combination with paged_results
Thanks to Andrei Popa <andrei.popa@next-gen.ro> for finding,
reporting and working with us to diagnose this issue!
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14331
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>
---
selftest/knownfail.d/asq | 1 +
source4/dsdb/tests/python/asq.py | 171 +++++++++++++++++++++++++++++++
source4/selftest/tests.py | 1 +
3 files changed, 173 insertions(+)
create mode 100644 selftest/knownfail.d/asq
create mode 100644 source4/dsdb/tests/python/asq.py
diff --git a/selftest/knownfail.d/asq b/selftest/knownfail.d/asq
new file mode 100644
index 00000000000..eb0e3e0aba1
--- /dev/null
+++ b/selftest/knownfail.d/asq
@@ -0,0 +1 @@
+samba4.asq.python\(ad_dc_default\).__main__.ASQLDAPTest.test_asq_paged
\ No newline at end of file
diff --git a/source4/dsdb/tests/python/asq.py b/source4/dsdb/tests/python/asq.py
new file mode 100644
index 00000000000..a32c9f40cd3
--- /dev/null
+++ b/source4/dsdb/tests/python/asq.py
@@ -0,0 +1,171 @@
+#!/usr/bin/env python3
+#
+# Test ASQ LDAP control behaviour in Samba
+# Copyright (C) Andrew Bartlett 2019-2020
+#
+# Based on Unit tests for the notification control
+# Copyright (C) Stefan Metzmacher 2016
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+import optparse
+import sys
+import os
+import random
+
+sys.path.insert(0, "bin/python")
+import samba
+from samba.tests.subunitrun import SubunitOptions, TestProgram
+
+import samba.getopt as options
+
+from samba.auth import system_session
+from samba import ldb
+from samba.samdb import SamDB
+from samba.ndr import ndr_unpack
+from samba import gensec
+from samba.credentials import Credentials
+import samba.tests
+
+from ldb import SCOPE_SUBTREE, SCOPE_ONELEVEL, SCOPE_BASE, LdbError
+from ldb import ERR_TIME_LIMIT_EXCEEDED, ERR_ADMIN_LIMIT_EXCEEDED, ERR_UNWILLING_TO_PERFORM
+from ldb import Message
+
+parser = optparse.OptionParser("large_ldap.py [options] <host>")
+sambaopts = options.SambaOptions(parser)
+parser.add_option_group(sambaopts)
+parser.add_option_group(options.VersionOptions(parser))
+# use command line creds if available
+credopts = options.CredentialsOptions(parser)
+parser.add_option_group(credopts)
+subunitopts = SubunitOptions(parser)
+parser.add_option_group(subunitopts)
+opts, args = parser.parse_args()
+
+if len(args) < 1:
+ parser.print_usage()
+ sys.exit(1)
+
+url = args[0]
+
+lp = sambaopts.get_loadparm()
+creds = credopts.get_credentials(lp)
+
+
+class ASQLDAPTest(samba.tests.TestCase):
+
+ def setUp(self):
+ super(ASQLDAPTest, self).setUp()
+ self.ldb = samba.Ldb(url, credentials=creds, session_info=system_session(lp), lp=lp)
+ self.base_dn = self.ldb.get_default_basedn()
+ self.NAME_ASQ="asq_" + format(random.randint(0, 99999), "05")
+ self.OU_NAME_ASQ= self.NAME_ASQ + "_ou"
+ self.ou_dn = ldb.Dn(self.ldb, "ou=" + self.OU_NAME_ASQ + "," + str(self.base_dn))
+
+ samba.tests.delete_force(self.ldb, self.ou_dn,
+ controls=['tree_delete:1'])
+
+ self.ldb.add({
+ "dn": self.ou_dn,
+ "objectclass": "organizationalUnit",
+ "ou": self.OU_NAME_ASQ})
+
+ self.members = []
+ self.members2 = []
+
+ for x in range(20):
+ name = self.NAME_ASQ + "_" + str(x)
+ dn = ldb.Dn(self.ldb,
+ "cn=" + name + "," + str(self.ou_dn))
+ self.members.append(dn)
+ self.ldb.add({
+ "dn": dn,
+ "objectclass": "group"})
+
+ for x in range(20):
+ name = self.NAME_ASQ + "_" + str(x + 20)
+ dn = ldb.Dn(self.ldb,
+ "cn=" + name + "," + str(self.ou_dn))
+ self.members2.append(dn)
+ self.ldb.add({
+ "dn": dn,
+ "objectclass": "group",
+ "member": [str(x) for x in self.members]})
+
+ name = self.NAME_ASQ + "_" + str(x + 40)
+ self.top_dn = ldb.Dn(self.ldb,
+ "cn=" + name + "," + str(self.ou_dn))
+ self.ldb.add({
+ "dn": self.top_dn,
+ "objectclass": "group",
+ "member": [str(x) for x in self.members2]})
+
+ def tearDown(self):
+ samba.tests.delete_force(self.ldb, self.ou_dn,
+ controls=['tree_delete:1'])
+
+ def test_asq(self):
+ """Testing ASQ behaviour.
+
+ ASQ is very strange, it turns a BASE search into a search for
+ all the objects pointed to by the specified attribute,
+ returning multiple entries!
+
+ """
+
+ msgs = self.ldb.search(base=self.top_dn,
+ scope=ldb.SCOPE_BASE,
+ attrs=["objectGUID", "cn", "member"],
+ controls=["asq:1:member"])
+
+ self.assertEqual(len(msgs), 20)
+
+ for msg in msgs:
+ self.assertNotEqual(msg.dn, self.top_dn)
+ self.assertIn(msg.dn, self.members2)
+ for group in msg["member"]:
+ self.assertIn(ldb.Dn(self.ldb, str(group)),
+ self.members)
+
+ def test_asq_paged(self):
+ """Testing ASQ behaviour with paged_results set.
+
+ ASQ is very strange, it turns a BASE search into a search for
+ all the objects pointed to by the specified attribute,
+ returning multiple entries!
+
+ """
+
+ msgs = self.ldb.search(base=self.top_dn,
+ scope=ldb.SCOPE_BASE,
+ attrs=["objectGUID", "cn", "member"],
+ controls=["asq:1:member",
+ "paged_results:1:1024"])
+
+ self.assertEqual(len(msgs), 20)
+
+ for msg in msgs:
+ self.assertNotEqual(msg.dn, self.top_dn)
+ self.assertIn(msg.dn, self.members2)
+ for group in msg["member"]:
+ self.assertIn(ldb.Dn(self.ldb, str(group)),
+ self.members)
+
+if "://" not in url:
+ if os.path.isfile(url):
+ url = "tdb://%s" % url
+ else:
+ url = "ldap://%s" % url
+
+TestProgram(module=__name__, opts=subunitopts)
diff --git a/source4/selftest/tests.py b/source4/selftest/tests.py
index ae2b10ae659..52db18a872b 100755
--- a/source4/selftest/tests.py
+++ b/source4/selftest/tests.py
@@ -885,6 +885,7 @@ plantestsuite_loadlist("samba4.tokengroups.krb5.python(ad_dc_default)", "ad_dc_d
plantestsuite_loadlist("samba4.tokengroups.ntlm.python(ad_dc_default)", "ad_dc_default:local", [python, os.path.join(DSDB_PYTEST_DIR, "token_group.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN', '-k', 'no', '$LOADLIST', '$LISTOPT'])
plantestsuite("samba4.sam.python(fl2008r2dc)", "fl2008r2dc", [python, os.path.join(DSDB_PYTEST_DIR, "sam.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
plantestsuite("samba4.sam.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "sam.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
+plantestsuite("samba4.asq.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "asq.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
plantestsuite("samba4.user_account_control.python(ad_dc_default)", "ad_dc_default", [python, os.path.join(DSDB_PYTEST_DIR, "user_account_control.py"), '$SERVER', '-U"$USERNAME%$PASSWORD"', '--workgroup=$DOMAIN'])
for env in ['ad_dc_default:local', 'schema_dc:local']:
--
2.17.1

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From 34f9e6e969913629f9241522020c5895dc9636dc Mon Sep 17 00:00:00 2001
From: Andrew Bartlett <abartlet@samba.org>
Date: Wed, 11 Mar 2020 16:43:31 +1300
Subject: [PATCH 3/4] CVE-2020-10700: dsdb: Do not permit the ASQ control for
the GUID search in paged_results
ASQ is a very strange control and a BASE search can return multiple results
that are NOT the requested DN, but the DNs pointed to by it!
Thanks to Andrei Popa <andrei.popa@next-gen.ro> for finding,
reporting and working with us to diagnose this issue!
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14331
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>
---
selftest/knownfail.d/asq | 1 -
source4/dsdb/samdb/ldb_modules/paged_results.c | 18 +++++++++++++-----
2 files changed, 13 insertions(+), 6 deletions(-)
delete mode 100644 selftest/knownfail.d/asq
diff --git a/selftest/knownfail.d/asq b/selftest/knownfail.d/asq
deleted file mode 100644
index eb0e3e0aba1..00000000000
--- a/selftest/knownfail.d/asq
+++ /dev/null
@@ -1 +0,0 @@
-samba4.asq.python\(ad_dc_default\).__main__.ASQLDAPTest.test_asq_paged
\ No newline at end of file
diff --git a/source4/dsdb/samdb/ldb_modules/paged_results.c b/source4/dsdb/samdb/ldb_modules/paged_results.c
index 940d2254fb0..dc211dd18ce 100644
--- a/source4/dsdb/samdb/ldb_modules/paged_results.c
+++ b/source4/dsdb/samdb/ldb_modules/paged_results.c
@@ -483,8 +483,14 @@ paged_results_copy_down_controls(TALLOC_CTX *mem_ctx,
if (control->oid == NULL) {
continue;
}
- if (strncmp(control->oid, LDB_CONTROL_PAGED_RESULTS_OID,
- sizeof(LDB_CONTROL_PAGED_RESULTS_OID)) == 0) {
+ if (strcmp(control->oid, LDB_CONTROL_PAGED_RESULTS_OID) == 0) {
+ continue;
+ }
+ /*
+ * ASQ changes everything, do not copy it down for the
+ * per-GUID search
+ */
+ if (strcmp(control->oid, LDB_CONTROL_ASQ_OID) == 0) {
continue;
}
new_controls[j] = talloc_steal(new_controls, control);
@@ -534,21 +540,23 @@ static bool paged_controls_same(struct ldb_request *req,
num_non_null_req_controls = 0;
for (i=0; req->controls[i] != NULL; i++) {
- if (req->controls[i]->oid != NULL) {
+ if (req->controls[i]->oid != NULL &&
+ strcmp(req->controls[i]->oid,
+ LDB_CONTROL_ASQ_OID) != 0) {
num_non_null_req_controls++;
}
}
/* At this point we have the number of non-null entries for both
* control lists and we know that:
- * 1. down_controls does not contain the paged control
+ * 1. down_controls does not contain the paged control or ASQ
* (because paged_results_copy_down_controls excludes it)
* 2. req->controls does contain the paged control
* (because this function is only called if this is true)
* 3. down_controls is a subset of non-null controls in req->controls
* (checked above)
* So to confirm that the two lists are identical except for the paged
- * control, all we need to check is: */
+ * control and possibly ASQ, all we need to check is: */
if (num_non_null_req_controls == num_down_controls + 1) {
return true;
}
--
2.17.1

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@ -0,0 +1,547 @@
From b01952c6fb15b92fff3ad1bf8f1cf579875e5483 Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Fri, 3 Apr 2020 12:18:03 +1300
Subject: [PATCH 1/8] CVE-2020-10704: lib util asn1: Add ASN.1 max tree depth
Add maximum parse tree depth to the call to asn1_init, which will be
used to limit the depth of the ASN.1 parse tree.
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
auth/gensec/gensec_util.c | 2 +-
lib/util/asn1.c | 17 +++++++++-
lib/util/asn1.h | 9 +++++-
lib/util/tests/asn1_tests.c | 2 +-
libcli/auth/spnego_parse.c | 6 ++--
libcli/cldap/cldap.c | 2 +-
libcli/ldap/ldap_message.c | 2 +-
source3/lib/tldap.c | 4 +--
source3/lib/tldap_util.c | 4 +--
source3/libsmb/clispnego.c | 4 +--
source3/torture/torture.c | 2 +-
source4/auth/gensec/gensec_krb5.c | 4 +--
source4/ldap_server/ldap_server.c | 2 +-
source4/libcli/ldap/ldap_client.c | 2 +-
source4/libcli/ldap/ldap_controls.c | 48 ++++++++++++++---------------
15 files changed, 66 insertions(+), 44 deletions(-)
diff --git a/auth/gensec/gensec_util.c b/auth/gensec/gensec_util.c
index 20c9c2a1fbb..e185acc0c20 100644
--- a/auth/gensec/gensec_util.c
+++ b/auth/gensec/gensec_util.c
@@ -76,7 +76,7 @@ NTSTATUS gensec_generate_session_info_pac(TALLOC_CTX *mem_ctx,
static bool gensec_gssapi_check_oid(const DATA_BLOB *blob, const char *oid)
{
bool ret = false;
- struct asn1_data *data = asn1_init(NULL);
+ struct asn1_data *data = asn1_init(NULL, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
diff --git a/lib/util/asn1.c b/lib/util/asn1.c
index 51da5424956..ec6e674ce20 100644
--- a/lib/util/asn1.c
+++ b/lib/util/asn1.c
@@ -36,15 +36,19 @@ struct asn1_data {
off_t ofs;
struct nesting *nesting;
bool has_error;
+ unsigned depth;
+ unsigned max_depth;
};
/* allocate an asn1 structure */
-struct asn1_data *asn1_init(TALLOC_CTX *mem_ctx)
+struct asn1_data *asn1_init(TALLOC_CTX *mem_ctx, unsigned max_depth)
{
struct asn1_data *ret = talloc_zero(mem_ctx, struct asn1_data);
if (ret == NULL) {
DEBUG(0,("asn1_init failed! out of memory\n"));
+ return ret;
}
+ ret->max_depth = max_depth;
return ret;
}
@@ -480,6 +484,11 @@ bool asn1_check_BOOLEAN(struct asn1_data *data, bool v)
/* load a struct asn1_data structure with a lump of data, ready to be parsed */
bool asn1_load(struct asn1_data *data, DATA_BLOB blob)
{
+ /*
+ * Save the maximum depth
+ */
+ unsigned max_depth = data->max_depth;
+
ZERO_STRUCTP(data);
data->data = (uint8_t *)talloc_memdup(data, blob.data, blob.length);
if (!data->data) {
@@ -487,6 +496,7 @@ bool asn1_load(struct asn1_data *data, DATA_BLOB blob)
return false;
}
data->length = blob.length;
+ data->max_depth = max_depth;
return true;
}
@@ -1103,9 +1113,14 @@ bool asn1_extract_blob(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
*/
void asn1_load_nocopy(struct asn1_data *data, uint8_t *buf, size_t len)
{
+ /*
+ * Save max_depth
+ */
+ unsigned max_depth = data->max_depth;
ZERO_STRUCTP(data);
data->data = buf;
data->length = len;
+ data->max_depth = max_depth;
}
int asn1_peek_full_tag(DATA_BLOB blob, uint8_t tag, size_t *packet_size)
diff --git a/lib/util/asn1.h b/lib/util/asn1.h
index ddd69863574..fc365724e93 100644
--- a/lib/util/asn1.h
+++ b/lib/util/asn1.h
@@ -45,7 +45,14 @@ typedef struct asn1_data ASN1_DATA;
#define ASN1_MAX_OIDS 20
-struct asn1_data *asn1_init(TALLOC_CTX *mem_ctx);
+/*
+ * The maximum permitted depth for an ASN.1 parse tree, the limit is chosen
+ * to align with the value for windows. Note that this value will trigger
+ * ASAN stack overflow errors.
+ */
+#define ASN1_MAX_TREE_DEPTH 512
+
+struct asn1_data *asn1_init(TALLOC_CTX *mem_ctx, unsigned max_depth);
void asn1_free(struct asn1_data *data);
bool asn1_has_error(const struct asn1_data *data);
void asn1_set_error(struct asn1_data *data);
diff --git a/lib/util/tests/asn1_tests.c b/lib/util/tests/asn1_tests.c
index e4b386ad785..ab5262c4ffb 100644
--- a/lib/util/tests/asn1_tests.c
+++ b/lib/util/tests/asn1_tests.c
@@ -330,7 +330,7 @@ static bool test_asn1_Integer(struct torture_context *tctx)
DATA_BLOB blob;
int val;
- data = asn1_init(mem_ctx);
+ data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) {
goto err;
}
diff --git a/libcli/auth/spnego_parse.c b/libcli/auth/spnego_parse.c
index f538b44552c..f7f19b10778 100644
--- a/libcli/auth/spnego_parse.c
+++ b/libcli/auth/spnego_parse.c
@@ -296,7 +296,7 @@ ssize_t spnego_read_data(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct spnego_data
return ret;
}
- asn1 = asn1_init(mem_ctx);
+ asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
return -1;
}
@@ -339,7 +339,7 @@ ssize_t spnego_read_data(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct spnego_data
ssize_t spnego_write_data(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, struct spnego_data *spnego)
{
- struct asn1_data *asn1 = asn1_init(mem_ctx);
+ struct asn1_data *asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
ssize_t ret = -1;
if (asn1 == NULL) {
@@ -411,7 +411,7 @@ bool spnego_write_mech_types(TALLOC_CTX *mem_ctx,
DATA_BLOB *blob)
{
bool ret = false;
- struct asn1_data *asn1 = asn1_init(mem_ctx);
+ struct asn1_data *asn1 = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
return false;
diff --git a/libcli/cldap/cldap.c b/libcli/cldap/cldap.c
index daba37a21d7..8fa9ce0b273 100644
--- a/libcli/cldap/cldap.c
+++ b/libcli/cldap/cldap.c
@@ -229,7 +229,7 @@ static bool cldap_socket_recv_dgram(struct cldap_socket *c,
goto error;
}
- asn1 = asn1_init(in);
+ asn1 = asn1_init(in, ASN1_MAX_TREE_DEPTH);
if (!asn1) {
goto nomem;
}
diff --git a/libcli/ldap/ldap_message.c b/libcli/ldap/ldap_message.c
index f21598374a1..ba82bddeab1 100644
--- a/libcli/ldap/ldap_message.c
+++ b/libcli/ldap/ldap_message.c
@@ -390,7 +390,7 @@ _PUBLIC_ bool ldap_encode(struct ldap_message *msg,
const struct ldap_control_handler *control_handlers,
DATA_BLOB *result, TALLOC_CTX *mem_ctx)
{
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
int i, j;
if (!data) return false;
diff --git a/source3/lib/tldap.c b/source3/lib/tldap.c
index d6c6e8859a6..bf5fc05d785 100644
--- a/source3/lib/tldap.c
+++ b/source3/lib/tldap.c
@@ -632,7 +632,7 @@ static void tldap_msg_received(struct tevent_req *subreq)
goto fail;
}
- data = asn1_init(talloc_tos());
+ data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
if (data == NULL) {
status = TLDAP_NO_MEMORY;
goto fail;
@@ -763,7 +763,7 @@ static struct tevent_req *tldap_req_create(TALLOC_CTX *mem_ctx,
if (req == NULL) {
return NULL;
}
- state->out = asn1_init(state);
+ state->out = asn1_init(state, ASN1_MAX_TREE_DEPTH);
if (state->out == NULL) {
goto err;
}
diff --git a/source3/lib/tldap_util.c b/source3/lib/tldap_util.c
index 1b86962a32e..168932a8a96 100644
--- a/source3/lib/tldap_util.c
+++ b/source3/lib/tldap_util.c
@@ -644,7 +644,7 @@ static struct tevent_req *tldap_ship_paged_search(
struct tldap_control *pgctrl;
struct asn1_data *asn1 = NULL;
- asn1 = asn1_init(state);
+ asn1 = asn1_init(state, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
return NULL;
}
@@ -783,7 +783,7 @@ static void tldap_search_paged_done(struct tevent_req *subreq)
TALLOC_FREE(state->cookie.data);
- asn1 = asn1_init(talloc_tos());
+ asn1 = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
if (tevent_req_nomem(asn1, req)) {
return;
}
diff --git a/source3/libsmb/clispnego.c b/source3/libsmb/clispnego.c
index 4a0fbcd73af..1608f6a9960 100644
--- a/source3/libsmb/clispnego.c
+++ b/source3/libsmb/clispnego.c
@@ -50,7 +50,7 @@ bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
*secblob = data_blob_null;
}
- data = asn1_init(talloc_tos());
+ data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
if (data == NULL) {
return false;
}
@@ -171,7 +171,7 @@ DATA_BLOB spnego_gen_krb5_wrap(TALLOC_CTX *ctx, const DATA_BLOB ticket, const ui
ASN1_DATA *data;
DATA_BLOB ret = data_blob_null;
- data = asn1_init(talloc_tos());
+ data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
if (data == NULL) {
return data_blob_null;
}
diff --git a/source3/torture/torture.c b/source3/torture/torture.c
index a795e61125f..c4b0a7bc4f9 100644
--- a/source3/torture/torture.c
+++ b/source3/torture/torture.c
@@ -11370,7 +11370,7 @@ tldap_build_extended_control(enum tldap_extended_val val)
ZERO_STRUCT(empty_control);
if (val != EXTENDED_NONE) {
- data = asn1_init(talloc_tos());
+ data = asn1_init(talloc_tos(), ASN1_MAX_TREE_DEPTH);
if (!data) {
return NULL;
diff --git a/source4/auth/gensec/gensec_krb5.c b/source4/auth/gensec/gensec_krb5.c
index 0323da87d29..b735063656a 100644
--- a/source4/auth/gensec/gensec_krb5.c
+++ b/source4/auth/gensec/gensec_krb5.c
@@ -444,7 +444,7 @@ static DATA_BLOB gensec_gssapi_gen_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLO
struct asn1_data *data;
DATA_BLOB ret = data_blob_null;
- data = asn1_init(mem_ctx);
+ data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data || !ticket->data) {
return ret;
}
@@ -478,7 +478,7 @@ static DATA_BLOB gensec_gssapi_gen_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLO
static bool gensec_gssapi_parse_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, DATA_BLOB *ticket, uint8_t tok_id[2])
{
bool ret = false;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
int data_remaining;
if (!data) {
diff --git a/source4/ldap_server/ldap_server.c b/source4/ldap_server/ldap_server.c
index 709b7bcacfa..6d329329909 100644
--- a/source4/ldap_server/ldap_server.c
+++ b/source4/ldap_server/ldap_server.c
@@ -560,7 +560,7 @@ static void ldapsrv_call_read_done(struct tevent_req *subreq)
return;
}
- asn1 = asn1_init(call);
+ asn1 = asn1_init(call, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
ldapsrv_terminate_connection(conn, "no memory");
return;
diff --git a/source4/libcli/ldap/ldap_client.c b/source4/libcli/ldap/ldap_client.c
index da84adc7769..2d75af6af6e 100644
--- a/source4/libcli/ldap/ldap_client.c
+++ b/source4/libcli/ldap/ldap_client.c
@@ -284,7 +284,7 @@ static void ldap_connection_recv_done(struct tevent_req *subreq)
return;
}
- asn1 = asn1_init(conn);
+ asn1 = asn1_init(conn, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
TALLOC_FREE(msg);
ldap_error_handler(conn, NT_STATUS_NO_MEMORY);
diff --git a/source4/libcli/ldap/ldap_controls.c b/source4/libcli/ldap/ldap_controls.c
index 716ca148308..df012a158e0 100644
--- a/source4/libcli/ldap/ldap_controls.c
+++ b/source4/libcli/ldap/ldap_controls.c
@@ -32,7 +32,7 @@ static bool decode_server_sort_response(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB attr;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_sort_resp_control *lsrc;
if (!data) return false;
@@ -79,7 +79,7 @@ static bool decode_server_sort_request(void *mem_ctx, DATA_BLOB in, void *_out)
void **out = (void **)_out;
DATA_BLOB attr;
DATA_BLOB rule;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_server_sort_control **lssc;
int num;
@@ -166,7 +166,7 @@ static bool decode_extended_dn_request(void *mem_ctx, DATA_BLOB in, void *_out)
return true;
}
- data = asn1_init(mem_ctx);
+ data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
if (!asn1_load(data, in)) {
@@ -198,7 +198,7 @@ static bool decode_extended_dn_request(void *mem_ctx, DATA_BLOB in, void *_out)
static bool decode_sd_flags_request(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_sd_flags_control *lsdfc;
if (!data) return false;
@@ -232,7 +232,7 @@ static bool decode_sd_flags_request(void *mem_ctx, DATA_BLOB in, void *_out)
static bool decode_search_options_request(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_search_options_control *lsoc;
if (!data) return false;
@@ -267,7 +267,7 @@ static bool decode_paged_results_request(void *mem_ctx, DATA_BLOB in, void *_out
{
void **out = (void **)_out;
DATA_BLOB cookie;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_paged_control *lprc;
if (!data) return false;
@@ -316,7 +316,7 @@ static bool decode_dirsync_request(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB cookie;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_dirsync_control *ldc;
if (!data) return false;
@@ -372,7 +372,7 @@ static bool decode_asq_control(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB source_attribute;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_asq_control *lac;
if (!data) return false;
@@ -433,7 +433,7 @@ static bool decode_verify_name_request(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB name;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_verify_name_control *lvnc;
int len;
@@ -485,7 +485,7 @@ static bool decode_verify_name_request(void *mem_ctx, DATA_BLOB in, void *_out)
static bool encode_verify_name_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_verify_name_control *lvnc = talloc_get_type(in, struct ldb_verify_name_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
DATA_BLOB gc_utf16;
if (!data) return false;
@@ -528,7 +528,7 @@ static bool decode_vlv_request(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB assertion_value, context_id;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_vlv_req_control *lvrc;
if (!data) return false;
@@ -626,7 +626,7 @@ static bool decode_vlv_response(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
DATA_BLOB context_id;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct ldb_vlv_resp_control *lvrc;
if (!data) return false;
@@ -682,7 +682,7 @@ static bool decode_vlv_response(void *mem_ctx, DATA_BLOB in, void *_out)
static bool encode_server_sort_response(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_sort_resp_control *lsrc = talloc_get_type(in, struct ldb_sort_resp_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -716,7 +716,7 @@ static bool encode_server_sort_response(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_server_sort_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_server_sort_control **lssc = talloc_get_type(in, struct ldb_server_sort_control *);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
int num;
if (!data) return false;
@@ -782,7 +782,7 @@ static bool encode_extended_dn_request(void *mem_ctx, void *in, DATA_BLOB *out)
return true;
}
- data = asn1_init(mem_ctx);
+ data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -810,7 +810,7 @@ static bool encode_extended_dn_request(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_sd_flags_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_sd_flags_control *lsdfc = talloc_get_type(in, struct ldb_sd_flags_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -838,7 +838,7 @@ static bool encode_sd_flags_request(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_search_options_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_search_options_control *lsoc = talloc_get_type(in, struct ldb_search_options_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -866,7 +866,7 @@ static bool encode_search_options_request(void *mem_ctx, void *in, DATA_BLOB *ou
static bool encode_paged_results_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_paged_control *lprc = talloc_get_type(in, struct ldb_paged_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -901,7 +901,7 @@ static bool encode_paged_results_request(void *mem_ctx, void *in, DATA_BLOB *out
static bool encode_asq_control(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_asq_control *lac = talloc_get_type(in, struct ldb_asq_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -936,7 +936,7 @@ static bool encode_asq_control(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_dirsync_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_dirsync_control *ldc = talloc_get_type(in, struct ldb_dirsync_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -972,7 +972,7 @@ static bool encode_dirsync_request(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_vlv_request(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_vlv_req_control *lvrc = talloc_get_type(in, struct ldb_vlv_req_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -1040,7 +1040,7 @@ static bool encode_vlv_request(void *mem_ctx, void *in, DATA_BLOB *out)
static bool encode_vlv_response(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct ldb_vlv_resp_control *lvrc = talloc_get_type(in, struct ldb_vlv_resp_control);
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -1083,7 +1083,7 @@ static bool encode_openldap_dereference(void *mem_ctx, void *in, DATA_BLOB *out)
{
struct dsdb_openldap_dereference_control *control = talloc_get_type(in, struct dsdb_openldap_dereference_control);
int i,j;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
if (!data) return false;
@@ -1132,7 +1132,7 @@ static bool encode_openldap_dereference(void *mem_ctx, void *in, DATA_BLOB *out)
static bool decode_openldap_dereference(void *mem_ctx, DATA_BLOB in, void *_out)
{
void **out = (void **)_out;
- struct asn1_data *data = asn1_init(mem_ctx);
+ struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
struct dsdb_openldap_dereference_result_control *control;
struct dsdb_openldap_dereference_result **r = NULL;
int i = 0;
--
2.17.1

52
CVE-2020-10704-3.patch Normal file
View File

@ -0,0 +1,52 @@
Backport of:
From d3be674c3ffa3541e2ba757e2c6dfb32508db440 Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Wed, 8 Apr 2020 15:30:52 +1200
Subject: [PATCH 3/8] CVE-2020-10704: lib util asn1: Check parse tree depth
Check the current depth of the parse tree and reject the input if the
depth exceeds that passed to asn1_init
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
lib/util/asn1.c | 13 +++++++++++++
selftest/knownfail.d/ldap_message | 2 --
2 files changed, 13 insertions(+), 2 deletions(-)
delete mode 100644 selftest/knownfail.d/ldap_message
--- a/lib/util/asn1.c
+++ b/lib/util/asn1.c
@@ -647,6 +647,16 @@ bool asn1_start_tag(struct asn1_data *da
uint8_t b;
struct nesting *nesting;
+ /*
+ * Check the depth of the parse tree and prevent it from growing
+ * too large.
+ */
+ data->depth++;
+ if (data->depth > data->max_depth) {
+ data->has_error = true;
+ return false;
+ }
+
if (!asn1_read_uint8(data, &b))
return false;
@@ -703,6 +713,9 @@ bool asn1_end_tag(struct asn1_data *data
{
struct nesting *nesting;
+ if (data->depth > 0) {
+ data->depth--;
+ }
/* make sure we read it all */
if (asn1_tag_remaining(data) != 0) {
data->has_error = true;

96
CVE-2020-10704-5.patch Normal file
View File

@ -0,0 +1,96 @@
From 9944df6ef1e421331ea1ca773f7e5652262d5d1b Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Tue, 7 Apr 2020 09:09:01 +1200
Subject: [PATCH 5/8] CVE-2020-10704: smb.conf: Add max ldap request sizes
Add two new smb.conf parameters to control the maximum permitted ldap
request size.
Adds:
ldap max anonymous request size default 250Kb
ldap max authenticated request size default 16Mb
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
.../smbdotconf/ldap/ldapmaxanonrequest.xml | 18 ++++++++++++++++++
.../smbdotconf/ldap/ldapmaxauthrequest.xml | 18 ++++++++++++++++++
lib/param/loadparm.c | 5 +++++
source3/param/loadparm.c | 3 +++
4 files changed, 44 insertions(+)
create mode 100644 docs-xml/smbdotconf/ldap/ldapmaxanonrequest.xml
create mode 100644 docs-xml/smbdotconf/ldap/ldapmaxauthrequest.xml
--- /dev/null
+++ b/docs-xml/smbdotconf/ldap/ldapmaxanonrequest.xml
@@ -0,0 +1,18 @@
+<samba:parameter name="ldap max anonymous request size"
+ context="G"
+ type="integer"
+ xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
+<description>
+ <para>
+ This parameter specifies the maximum permitted size (in bytes)
+ for an LDAP request received on an anonymous connection.
+ </para>
+
+ <para>
+ If the request size exceeds this limit the request will be
+ rejected.
+ </para>
+</description>
+<value type="default">256000</value>
+<value type="example">500000</value>
+</samba:parameter>
--- /dev/null
+++ b/docs-xml/smbdotconf/ldap/ldapmaxauthrequest.xml
@@ -0,0 +1,18 @@
+<samba:parameter name="ldap max authenticated request size"
+ context="G"
+ type="integer"
+ xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
+<description>
+ <para>
+ This parameter specifies the maximum permitted size (in bytes)
+ for an LDAP request received on an authenticated connection.
+ </para>
+
+ <para>
+ If the request size exceeds this limit the request will be
+ rejected.
+ </para>
+</description>
+<value type="default">16777216</value>
+<value type="example">4194304</value>
+</samba:parameter>
--- a/lib/param/loadparm.c
+++ b/lib/param/loadparm.c
@@ -3027,6 +3027,11 @@ struct loadparm_context *loadparm_init(T
lpcfg_do_global_parameter(lp_ctx, "debug encryption", "no");
+ lpcfg_do_global_parameter(
+ lp_ctx, "ldap max anonymous request size", "256000");
+ lpcfg_do_global_parameter(
+ lp_ctx, "ldap max authenticated request size", "16777216");
+
for (i = 0; parm_table[i].label; i++) {
if (!(lp_ctx->flags[i] & FLAG_CMDLINE)) {
lp_ctx->flags[i] |= FLAG_DEFAULT;
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -956,6 +956,9 @@ static void init_globals(struct loadparm
Globals.prefork_backoff_increment = 10;
Globals.prefork_maximum_backoff = 120;
+ Globals.ldap_max_anonymous_request_size = 256000;
+ Globals.ldap_max_authenticated_request_size = 16777216;
+
/* Now put back the settings that were set with lp_set_cmdline() */
apply_lp_set_cmdline();
}

163
CVE-2020-10704-6.patch Normal file
View File

@ -0,0 +1,163 @@
Backport of:
From 85619363d3280346b2253fe44bf67d4881a53ebd Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Wed, 8 Apr 2020 15:32:22 +1200
Subject: [PATCH 6/8] CVE-2020-10704: S4 ldap server: Limit request sizes
Check the size of authenticated and anonymous ldap requests and reject
them if they exceed the limits in smb.conf
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
selftest/knownfail.d/ldap_raw | 1 -
source4/ldap_server/ldap_server.c | 96 ++++++++++++++++++++++++++++++-
2 files changed, 95 insertions(+), 2 deletions(-)
delete mode 100644 selftest/knownfail.d/ldap_raw
--- a/source4/ldap_server/ldap_server.c
+++ b/source4/ldap_server/ldap_server.c
@@ -441,6 +441,10 @@ static void ldapsrv_accept_tls_done(stru
}
static void ldapsrv_call_read_done(struct tevent_req *subreq);
+static NTSTATUS ldapsrv_packet_check(
+ void *private_data,
+ DATA_BLOB blob,
+ size_t *packet_size);
static bool ldapsrv_call_read_next(struct ldapsrv_connection *conn)
{
@@ -494,7 +498,7 @@ static bool ldapsrv_call_read_next(struc
conn->connection->event.ctx,
conn->sockets.active,
7, /* initial_read_size */
- ldap_full_packet,
+ ldapsrv_packet_check,
conn);
if (subreq == NULL) {
ldapsrv_terminate_connection(conn, "ldapsrv_call_read_next: "
@@ -520,6 +524,9 @@ static bool ldapsrv_call_read_next(struc
}
static void ldapsrv_call_process_done(struct tevent_req *subreq);
+static int ldapsrv_check_packet_size(
+ struct ldapsrv_connection *conn,
+ size_t size);
static void ldapsrv_call_read_done(struct tevent_req *subreq)
{
@@ -530,6 +537,7 @@ static void ldapsrv_call_read_done(struc
struct ldapsrv_call *call;
struct asn1_data *asn1;
DATA_BLOB blob;
+ int ret = LDAP_SUCCESS;
conn->sockets.read_req = NULL;
@@ -560,6 +568,14 @@ static void ldapsrv_call_read_done(struc
return;
}
+ ret = ldapsrv_check_packet_size(conn, blob.length);
+ if (ret != LDAP_SUCCESS) {
+ ldapsrv_terminate_connection(
+ conn,
+ "Request packet too large");
+ return;
+ }
+
asn1 = asn1_init(call, ASN1_MAX_TREE_DEPTH);
if (asn1 == NULL) {
ldapsrv_terminate_connection(conn, "no memory");
@@ -1362,6 +1378,84 @@ static void ldapsrv_post_fork(struct tas
}
}
+/*
+ * Check the size of an ldap request packet.
+ *
+ * For authenticated connections the maximum packet size is controlled by
+ * the smb.conf parameter "ldap max authenticated request size"
+ *
+ * For anonymous connections the maximum packet size is controlled by
+ * the smb.conf parameter "ldap max anonymous request size"
+ */
+static int ldapsrv_check_packet_size(
+ struct ldapsrv_connection *conn,
+ size_t size)
+{
+ bool is_anonymous = false;
+ size_t max_size = 0;
+
+ max_size = lpcfg_ldap_max_anonymous_request_size(conn->lp_ctx);
+ if (size <= max_size) {
+ return LDAP_SUCCESS;
+ }
+
+ /*
+ * Request is larger than the maximum unauthenticated request size.
+ * As this code is called frequently we avoid calling
+ * security_token_is_anonymous if possible
+ */
+ if (conn->session_info != NULL &&
+ conn->session_info->security_token != NULL) {
+ is_anonymous = security_token_is_anonymous(
+ conn->session_info->security_token);
+ }
+
+ if (is_anonymous) {
+ DBG_WARNING(
+ "LDAP request size (%zu) exceeds (%zu)\n",
+ size,
+ max_size);
+ return LDAP_UNWILLING_TO_PERFORM;
+ }
+
+ max_size = lpcfg_ldap_max_authenticated_request_size(conn->lp_ctx);
+ if (size > max_size) {
+ DBG_WARNING(
+ "LDAP request size (%zu) exceeds (%zu)\n",
+ size,
+ max_size);
+ return LDAP_UNWILLING_TO_PERFORM;
+ }
+ return LDAP_SUCCESS;
+
+}
+
+/*
+ * Check that the blob contains enough data to be a valid packet
+ * If there is a packet header check the size to ensure that it does not
+ * exceed the maximum sizes.
+ *
+ */
+static NTSTATUS ldapsrv_packet_check(
+ void *private_data,
+ DATA_BLOB blob,
+ size_t *packet_size)
+{
+ NTSTATUS ret;
+ struct ldapsrv_connection *conn = private_data;
+ int result = LDB_SUCCESS;
+
+ ret = ldap_full_packet(private_data, blob, packet_size);
+ if (!NT_STATUS_IS_OK(ret)) {
+ return ret;
+ }
+ result = ldapsrv_check_packet_size(conn, *packet_size);
+ if (result != LDAP_SUCCESS) {
+ return NT_STATUS_LDAP(result);
+ }
+ return NT_STATUS_OK;
+}
+
NTSTATUS server_service_ldap_init(TALLOC_CTX *ctx)
{
static const struct service_details details = {

211
CVE-2020-10704-7.patch Normal file
View File

@ -0,0 +1,211 @@
Backport of:
From 9be121c7055fde841be15f8d570ff49801b68bff Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Wed, 8 Apr 2020 08:49:23 +1200
Subject: [PATCH 7/8] CVE-2020-10704: libcli ldap_message: Add search size
limits to ldap_decode
Add search request size limits to ldap_decode calls.
The ldap server uses the smb.conf variable
"ldap max search request size" which defaults to 250Kb.
For cldap the limit is hard coded as 4096.
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
.../smbdotconf/ldap/ldapmaxsearchrequest.xml | 18 ++++++++++++++
lib/param/loadparm.c | 2 ++
libcli/cldap/cldap.c | 18 +++++++++++---
libcli/ldap/ldap_message.c | 1 +
libcli/ldap/ldap_message.h | 5 ++++
libcli/ldap/tests/ldap_message_test.c | 24 +++++++++++++++----
source3/param/loadparm.c | 1 +
source4/ldap_server/ldap_server.c | 10 ++++++--
source4/libcli/ldap/ldap_client.c | 3 ++-
9 files changed, 72 insertions(+), 10 deletions(-)
create mode 100644 docs-xml/smbdotconf/ldap/ldapmaxsearchrequest.xml
--- /dev/null
+++ b/docs-xml/smbdotconf/ldap/ldapmaxsearchrequest.xml
@@ -0,0 +1,18 @@
+<samba:parameter name="ldap max search request size"
+ context="G"
+ type="integer"
+ xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
+<description>
+ <para>
+ This parameter specifies the maximum permitted size (in bytes)
+ for an LDAP search request.
+ </para>
+
+ <para>
+ If the request size exceeds this limit the request will be
+ rejected.
+ </para>
+</description>
+<value type="default">256000</value>
+<value type="example">4194304</value>
+</samba:parameter>
--- a/lib/param/loadparm.c
+++ b/lib/param/loadparm.c
@@ -3031,6 +3031,8 @@ struct loadparm_context *loadparm_init(T
lp_ctx, "ldap max anonymous request size", "256000");
lpcfg_do_global_parameter(
lp_ctx, "ldap max authenticated request size", "16777216");
+ lpcfg_do_global_parameter(
+ lp_ctx, "ldap max search request size", "256000");
for (i = 0; parm_table[i].label; i++) {
if (!(lp_ctx->flags[i] & FLAG_CMDLINE)) {
--- a/libcli/cldap/cldap.c
+++ b/libcli/cldap/cldap.c
@@ -111,6 +111,11 @@ struct cldap_search_state {
struct tevent_req *req;
};
+/*
+ * For CLDAP we limit the maximum search request size to 4kb
+ */
+#define MAX_SEARCH_REQUEST 4096
+
static int cldap_socket_destructor(struct cldap_socket *c)
{
while (c->searches.list) {
@@ -224,6 +229,9 @@ static bool cldap_socket_recv_dgram(stru
void *p;
struct cldap_search_state *search;
NTSTATUS status;
+ struct ldap_request_limits limits = {
+ .max_search_size = MAX_SEARCH_REQUEST
+ };
if (in->recv_errno != 0) {
goto error;
@@ -242,7 +250,7 @@ static bool cldap_socket_recv_dgram(stru
}
/* this initial decode is used to find the message id */
- status = ldap_decode(asn1, NULL, in->ldap_msg);
+ status = ldap_decode(asn1, &limits, NULL, in->ldap_msg);
if (!NT_STATUS_IS_OK(status)) {
goto nterror;
}
@@ -770,6 +778,9 @@ NTSTATUS cldap_search_recv(struct tevent
struct cldap_search_state);
struct ldap_message *ldap_msg;
NTSTATUS status;
+ struct ldap_request_limits limits = {
+ .max_search_size = MAX_SEARCH_REQUEST
+ };
if (tevent_req_is_nterror(req, &status)) {
goto failed;
@@ -780,7 +791,7 @@ NTSTATUS cldap_search_recv(struct tevent
goto nomem;
}
- status = ldap_decode(state->response.asn1, NULL, ldap_msg);
+ status = ldap_decode(state->response.asn1, &limits, NULL, ldap_msg);
if (!NT_STATUS_IS_OK(status)) {
goto failed;
}
@@ -796,7 +807,8 @@ NTSTATUS cldap_search_recv(struct tevent
*io->out.response = ldap_msg->r.SearchResultEntry;
/* decode the 2nd part */
- status = ldap_decode(state->response.asn1, NULL, ldap_msg);
+ status = ldap_decode(
+ state->response.asn1, &limits, NULL, ldap_msg);
if (!NT_STATUS_IS_OK(status)) {
goto failed;
}
--- a/libcli/ldap/ldap_message.c
+++ b/libcli/ldap/ldap_message.c
@@ -1162,6 +1162,7 @@ static bool ldap_decode_attribs(TALLOC_C
/* This routine returns LDAP status codes */
_PUBLIC_ NTSTATUS ldap_decode(struct asn1_data *data,
+ const struct ldap_request_limits *limits,
const struct ldap_control_handler *control_handlers,
struct ldap_message *msg)
{
--- a/libcli/ldap/ldap_message.h
+++ b/libcli/ldap/ldap_message.h
@@ -213,10 +213,15 @@ struct ldap_control_handler {
bool (*encode)(void *mem_ctx, void *in, DATA_BLOB *out);
};
+struct ldap_request_limits {
+ unsigned max_search_size;
+};
+
struct asn1_data;
struct ldap_message *new_ldap_message(TALLOC_CTX *mem_ctx);
NTSTATUS ldap_decode(struct asn1_data *data,
+ const struct ldap_request_limits *limits,
const struct ldap_control_handler *control_handlers,
struct ldap_message *msg);
bool ldap_encode(struct ldap_message *msg,
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -958,6 +958,7 @@ static void init_globals(struct loadparm
Globals.ldap_max_anonymous_request_size = 256000;
Globals.ldap_max_authenticated_request_size = 16777216;
+ Globals.ldap_max_search_request_size = 256000;
/* Now put back the settings that were set with lp_set_cmdline() */
apply_lp_set_cmdline();
--- a/source4/ldap_server/ldap_server.c
+++ b/source4/ldap_server/ldap_server.c
@@ -538,6 +538,7 @@ static void ldapsrv_call_read_done(struc
struct asn1_data *asn1;
DATA_BLOB blob;
int ret = LDAP_SUCCESS;
+ struct ldap_request_limits limits = {0};
conn->sockets.read_req = NULL;
@@ -593,8 +594,13 @@ static void ldapsrv_call_read_done(struc
return;
}
- status = ldap_decode(asn1, samba_ldap_control_handlers(),
- call->request);
+ limits.max_search_size =
+ lpcfg_ldap_max_search_request_size(conn->lp_ctx);
+ status = ldap_decode(
+ asn1,
+ &limits,
+ samba_ldap_control_handlers(),
+ call->request);
if (!NT_STATUS_IS_OK(status)) {
ldapsrv_terminate_connection(conn, nt_errstr(status));
return;
--- a/source4/libcli/ldap/ldap_client.c
+++ b/source4/libcli/ldap/ldap_client.c
@@ -277,6 +277,7 @@ static void ldap_connection_recv_done(st
struct ldap_message *msg;
struct asn1_data *asn1;
DATA_BLOB blob;
+ struct ldap_request_limits limits = {0};
msg = talloc_zero(conn, struct ldap_message);
if (msg == NULL) {
@@ -306,7 +307,7 @@ static void ldap_connection_recv_done(st
asn1_load_nocopy(asn1, blob.data, blob.length);
- status = ldap_decode(asn1, samba_ldap_control_handlers(), msg);
+ status = ldap_decode(asn1, &limits, samba_ldap_control_handlers(), msg);
asn1_free(asn1);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(msg);

66
CVE-2020-10704-8.patch Normal file
View File

@ -0,0 +1,66 @@
From ee3156c76b86c11829f6f3fe1e3c940b45899c56 Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Wed, 8 Apr 2020 10:46:44 +1200
Subject: [PATCH 8/8] CVE-2020-10704 libcli ldap: Check search request lengths.
Check the search request lengths against the limits passed to
ldap_decode.
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20454
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14334
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
lib/util/asn1.c | 7 +++++++
lib/util/asn1.h | 1 +
libcli/ldap/ldap_message.c | 4 ++++
3 files changed, 12 insertions(+)
diff --git a/lib/util/asn1.c b/lib/util/asn1.c
index ee3cff9cb65..32d7981d28f 100644
--- a/lib/util/asn1.c
+++ b/lib/util/asn1.c
@@ -1159,3 +1159,10 @@ int asn1_peek_full_tag(DATA_BLOB blob, uint8_t tag, size_t *packet_size)
*packet_size = size;
return 0;
}
+
+/*
+ * Get the length of the ASN.1 data
+ */
+size_t asn1_get_length(const struct asn1_data *asn1) {
+ return asn1->length;
+}
diff --git a/lib/util/asn1.h b/lib/util/asn1.h
index fc365724e93..de92a767f14 100644
--- a/lib/util/asn1.h
+++ b/lib/util/asn1.h
@@ -106,5 +106,6 @@ bool asn1_extract_blob(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
DATA_BLOB *pblob);
void asn1_load_nocopy(struct asn1_data *data, uint8_t *buf, size_t len);
int asn1_peek_full_tag(DATA_BLOB blob, uint8_t tag, size_t *packet_size);
+size_t asn1_get_length(const struct asn1_data *asn1);
#endif /* _ASN_1_H */
diff --git a/libcli/ldap/ldap_message.c b/libcli/ldap/ldap_message.c
index d38fa0b3b61..69a48279532 100644
--- a/libcli/ldap/ldap_message.c
+++ b/libcli/ldap/ldap_message.c
@@ -1259,7 +1259,11 @@ _PUBLIC_ NTSTATUS ldap_decode(struct asn1_data *data,
struct ldap_SearchRequest *r = &msg->r.SearchRequest;
int sizelimit, timelimit;
const char **attrs = NULL;
+ size_t request_size = asn1_get_length(data);
msg->type = LDAP_TAG_SearchRequest;
+ if (request_size > limits->max_search_size) {
+ goto prot_err;
+ }
if (!asn1_start_tag(data, tag)) goto prot_err;
if (!asn1_read_OctetString_talloc(msg, data, &r->basedn)) goto prot_err;
if (!asn1_read_enumerated(data, (int *)(void *)&(r->scope))) goto prot_err;
--
2.17.1

13
samba.spec
View File

@ -49,7 +49,7 @@
Name: samba Name: samba
Version: 4.11.6 Version: 4.11.6
Release: 5 Release: 6
Summary: A suite for Linux to interoperate with Windows Summary: A suite for Linux to interoperate with Windows
License: GPLv3+ and LGPLv3+ License: GPLv3+ and LGPLv3+
@ -69,6 +69,14 @@ Source201: README.downgrade
Patch100: 0000-use-gnutls-for-des-cbc.patch Patch100: 0000-use-gnutls-for-des-cbc.patch
Patch101: 0001-handle-removal-des-enctypes-from-krb5.patch Patch101: 0001-handle-removal-des-enctypes-from-krb5.patch
Patch102: 0002-samba-tool-create-working-private-krb5.conf.patch Patch102: 0002-samba-tool-create-working-private-krb5.conf.patch
Patch103: CVE-2020-10700-1.patch
Patch104: CVE-2020-10700-3.patch
Patch105: CVE-2020-10704-1.patch
Patch106: CVE-2020-10704-3.patch
Patch107: CVE-2020-10704-5.patch
Patch108: CVE-2020-10704-6.patch
Patch109: CVE-2020-10704-7.patch
Patch110: CVE-2020-10704-8.patch
BuildRequires: avahi-devel cups-devel dbus-devel docbook-style-xsl e2fsprogs-devel gawk gnupg2 gnutls-devel >= 3.4.7 gpgme-devel BuildRequires: avahi-devel cups-devel dbus-devel docbook-style-xsl e2fsprogs-devel gawk gnupg2 gnutls-devel >= 3.4.7 gpgme-devel
BuildRequires: jansson-devel krb5-devel >= %{required_mit_krb5} libacl-devel libaio-devel libarchive-devel libattr-devel BuildRequires: jansson-devel krb5-devel >= %{required_mit_krb5} libacl-devel libaio-devel libarchive-devel libattr-devel
@ -3079,6 +3087,9 @@ fi
%{_mandir}/man8/* %{_mandir}/man8/*
%changelog %changelog
* Wed May 20 2020 zhouyihang <zhouyihang3@huawei.com> - 4.11.6-6
- fix CVE-2020-10700,CVE-2020-10704
* Sat Mar 21 2020 songnannan <songnannan2@huawei.com> - 4.11.6-5 * Sat Mar 21 2020 songnannan <songnannan2@huawei.com> - 4.11.6-5
- bugfix about update - bugfix about update