From: Daniil Sarafannikov <sarafannikovda@sgu.ru>
Date: Thu, 11 Jun 2026 14:58:37 +0000 (+0400)
Subject: s4:dsdb: check if domain is not empty
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85d6edbd814fd01c3168402060b3a12cdec159f8;p=thirdparty%2Fsamba.git

s4:dsdb: check if domain is not empty

domain[strlen(domain)-1] leads to UB if strlen(domain) == 0,
so we add check that domain is not empty before accessing
the last symbol.

Pair-Programmed-With: Dmitriy Mikhalchenko <tascad@altlinux.org>
Signed-off-by: Daniil Sarafannikov <sarafannikovda@sgu.ru>
Reviewed-by: Anoop C S <anoopcs@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Jun 12 11:41:01 UTC 2026 on atb-devel-224
---

diff --git a/source4/dsdb/samdb/ldb_modules/netlogon.c b/source4/dsdb/samdb/ldb_modules/netlogon.c
index 479b3a6deec..c3d417e1cad 100644
--- a/source4/dsdb/samdb/ldb_modules/netlogon.c
+++ b/source4/dsdb/samdb/ldb_modules/netlogon.c
@@ -81,7 +81,7 @@ NTSTATUS fill_netlogon_samlogon_response(struct ldb_context *sam_ctx,
 	NTSTATUS status;
 
 	/* the domain parameter could have an optional trailing "." */
-	if (domain && domain[strlen(domain)-1] == '.') {
+	if (domain && domain[0] != '\0' && domain[strlen(domain)-1] == '.') {
 		domain = talloc_strndup(mem_ctx, domain, strlen(domain)-1);
 		NT_STATUS_HAVE_NO_MEMORY(domain);
 	}