From 26df81a00bf89ca00a3de2d9d3ede0599b55cd51 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn@samba.org>
Date: Tue, 23 Nov 2021 15:48:57 +0100
Subject: [PATCH] s3:winbind: Fix possible NULL pointer dereference

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14921
BUG: https://bugzilla.redhat.com/show_bug.cgi?id=2019888

Signed-off-by: Andreas Schneider <asn@samba.org>
Rewiewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit cbf312f02bc86f9325fb89f6f5441bc61fd3974f)
---
 source3/winbindd/winbindd_util.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/source3/winbindd/winbindd_util.c b/source3/winbindd/winbindd_util.c
index a8c510fafc6..175e05ae3ad 100644
--- a/source3/winbindd/winbindd_util.c
+++ b/source3/winbindd/winbindd_util.c
@@ -1784,6 +1784,9 @@ char *fill_domain_username_talloc(TALLOC_CTX *mem_ctx,
 	}
 
 	tmp_user = talloc_strdup(mem_ctx, user);
+	if (tmp_user == NULL) {
+		return NULL;
+	}
 	if (!strlower_m(tmp_user)) {
 		TALLOC_FREE(tmp_user);
 		return NULL;
-- 
2.34.1