From 6aa5d1f684f6bdbae46508347d093a8def27912a Mon Sep 17 00:00:00 2001 From: Douglas Bagnall Date: Fri, 17 May 2019 14:42:24 +1200 Subject: [PATCH] CVE-2019-12436 dsdb/paged_results: ignore successful results without messages So that we don't dereference result->msgs[0] when it doesn't exist. This can happen when the object has changed in such a way that it no longer matches the original search query. BUG: https://bugzilla.samba.org/show_bug.cgi?id=13951 Signed-off-by: Douglas Bagnall Reviewed-by: Andrew Bartlett Autobuild-User(master): Karolin Seeger Autobuild-Date(master): Wed Jun 19 08:16:39 UTC 2019 on sn-devel-184 --- .../dsdb/samdb/ldb_modules/paged_results.c | 3 +- source4/dsdb/tests/python/vlv.py | 50 ++++++++++++++++++- 2 files changed, 51 insertions(+), 2 deletions(-) diff --git a/source4/dsdb/samdb/ldb_modules/paged_results.c b/source4/dsdb/samdb/ldb_modules/paged_results.c index e70f462efed..940d2254fb0 100644 --- a/source4/dsdb/samdb/ldb_modules/paged_results.c +++ b/source4/dsdb/samdb/ldb_modules/paged_results.c @@ -266,7 +266,8 @@ static int paged_results(struct paged_context *ac) ret = paged_search_by_dn_guid(ac->module, ac, &result, guid, ac->req->op.search.attrs, ac->store->expr); - if (ret == LDAP_NO_SUCH_OBJECT /* TODO or no result */) { + if (ret == LDAP_NO_SUCH_OBJECT || + (ret == LDB_SUCCESS && result->count == 0)) { /* The thing isn't there TODO, which we quietly ignore and go on to send an extra one instead. */ diff --git a/source4/dsdb/tests/python/vlv.py b/source4/dsdb/tests/python/vlv.py index 29cc1718c78..2efcaa5e7a3 100644 --- a/source4/dsdb/tests/python/vlv.py +++ b/source4/dsdb/tests/python/vlv.py @@ -105,6 +105,7 @@ class TestsWithUserOU(samba.tests.TestCase): 'givenName': "abcdefghijklmnopqrstuvwxyz"[i % 26], "roomNumber": "%sbc" % (n - i), "carLicense": "后来经", + "facsimileTelephoneNumber": name, "employeeNumber": "%s%sx" % (abs(i * (99 - i)), '\n' * (i & 255)), "accountExpires": "%s" % (10 ** 9 + 1000000 * i), "msTSExpireDate4": "19%02d0101010000.0Z" % (i % 100), @@ -1338,7 +1339,7 @@ class PagedResultsTests(TestsWithUserOU): self.assertEqual(results, expected_results) - def test_paged_modify_during_search(self): + def test_paged_rename_during_search(self): expr = "(objectClass=*)" # Start new search @@ -1421,6 +1422,53 @@ class PagedResultsTests(TestsWithUserOU): self.assertEqual(results, expected_results) + def test_paged_modify_one_during_search(self): + prefix = "change_during_search_" + num_users = 5 + users = [self.create_user(i, num_users, prefix=prefix) + for i in range(num_users)] + expr = "(&(objectClass=user)(facsimileTelephoneNumber=%s*))" % (prefix) + + # Get the first page, then change the searched attribute and + # try for the second page. + results, cookie = self.paged_search(expr, page_size=1) + self.assertEqual(len(results), 1) + unwalked_users = [u for u in users if u['cn'] != results[0]] + self.assertEqual(len(unwalked_users), num_users-1) + + mod_dn = unwalked_users[0]['dn'] + self.ldb.modify_ldif("dn: %s\n" + "changetype: modify\n" + "replace: facsimileTelephoneNumber\n" + "facsimileTelephoneNumber: 123" % mod_dn) + + results, _ = self.paged_search(expr, cookie=cookie, + page_size=len(self.users)) + expected_cns = {u['cn'] for u in unwalked_users if u['dn'] != mod_dn} + self.assertEqual(set(results), expected_cns) + + def test_paged_modify_all_during_search(self): + prefix = "change_during_search_" + num_users = 5 + users = [self.create_user(i, num_users, prefix=prefix) + for i in range(num_users)] + expr = "(&(objectClass=user)(facsimileTelephoneNumber=%s*))" % (prefix) + + # Get the first page, then change the searched attribute and + # try for the second page. + results, cookie = self.paged_search(expr, page_size=1) + unwalked_users = [u for u in users if u['cn'] != results[0]] + + for u in users: + self.ldb.modify_ldif("dn: %s\n" + "changetype: modify\n" + "replace: facsimileTelephoneNumber\n" + "facsimileTelephoneNumber: 123" % u['dn']) + + results, _ = self.paged_search(expr, cookie=cookie, + page_size=len(self.users)) + self.assertEqual(results, []) + def assertPagedSearchRaises(self, err_num, expr, cookie, attrs=None, extra_ctrls=None): try: