From 595dd9fc4162dd70ad937db8669a0fddbbba9584 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Thu, 9 Jul 2020 21:49:25 +0200
Subject: [PATCH] CVE-2020-14323 winbind: Fix invalid lookupsids DoS

A lookupsids request without extra_data will lead to "state->domain==NULL",
which makes winbindd_lookupsids_recv trying to dereference it.

Reported by Bas Alberts of the GitHub Security Lab Team as GHSL-2020-134

Bug: https://bugzilla.samba.org/show_bug.cgi?id=14436
Signed-off-by: Volker Lendecke <vl@samba.org>
---
 source3/winbindd/winbindd_lookupsids.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source3/winbindd/winbindd_lookupsids.c b/source3/winbindd/winbindd_lookupsids.c
index d28b5fa9f01..a289fd86f0f 100644
--- a/source3/winbindd/winbindd_lookupsids.c
+++ b/source3/winbindd/winbindd_lookupsids.c
@@ -47,7 +47,7 @@ struct tevent_req *winbindd_lookupsids_send(TALLOC_CTX *mem_ctx,
 	DEBUG(3, ("lookupsids\n"));
 
 	if (request->extra_len == 0) {
-		tevent_req_done(req);
+		tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
 		return tevent_req_post(req, ev);
 	}
 	if (request->extra_data.data[request->extra_len-1] != '\0') {
-- 
2.29.2

From 0b259a48a70bde4dfd482e0720e593ae5a9c414a Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Thu, 9 Jul 2020 21:48:57 +0200
Subject: [PATCH] CVE-2020-14323 torture4: Add a simple test for invalid
 lookup_sids winbind call

We can't add this test before the fix, add it to knownfail and have the fix
remove the knownfail entry again. As this crashes winbind, many tests after
this one will fail.

Reported by Bas Alberts of the GitHub Security Lab Team as GHSL-2020-134

Bug: https://bugzilla.samba.org/show_bug.cgi?id=14436
Signed-off-by: Volker Lendecke <vl@samba.org>
---
 source4/torture/winbind/struct_based.c | 27 ++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/source4/torture/winbind/struct_based.c b/source4/torture/winbind/struct_based.c
index 9745b621ca9..71f248c0d61 100644
--- a/source4/torture/winbind/struct_based.c
+++ b/source4/torture/winbind/struct_based.c
@@ -1110,6 +1110,29 @@ static bool torture_winbind_struct_lookup_name_sid(struct torture_context *tortu
 	return true;
 }
 
+static bool torture_winbind_struct_lookup_sids_invalid(
+	struct torture_context *torture)
+{
+	struct winbindd_request req = {0};
+	struct winbindd_response rep = {0};
+	bool strict = torture_setting_bool(torture, "strict mode", false);
+	bool ok;
+
+	torture_comment(torture,
+			"Running WINBINDD_LOOKUP_SIDS (struct based)\n");
+
+	ok = true;
+	DO_STRUCT_REQ_REP_EXT(WINBINDD_LOOKUPSIDS, &req, &rep,
+			      NSS_STATUS_NOTFOUND,
+			      strict,
+			      ok=false,
+			      talloc_asprintf(
+				      torture,
+				      "invalid lookupsids succeeded"));
+
+	return ok;
+}
+
 struct torture_suite *torture_winbind_struct_init(TALLOC_CTX *ctx)
 {
 	struct torture_suite *suite = torture_suite_create(ctx, "struct");
@@ -1132,6 +1155,10 @@ struct torture_suite *torture_winbind_struct_init(TALLOC_CTX *ctx)
 	torture_suite_add_simple_test(suite, "getpwent", torture_winbind_struct_getpwent);
 	torture_suite_add_simple_test(suite, "endpwent", torture_winbind_struct_endpwent);
 	torture_suite_add_simple_test(suite, "lookup_name_sid", torture_winbind_struct_lookup_name_sid);
+	torture_suite_add_simple_test(
+		suite,
+		"lookup_sids_invalid",
+		torture_winbind_struct_lookup_sids_invalid);
 
 	suite->description = talloc_strdup(suite, "WINBIND - struct based protocol tests");
 
-- 
2.29.2