From: Andreas Schneider <asn@samba.org>
Date: Wed, 6 Aug 2025 12:40:34 +0000 (+0200)
Subject: auth:creds: Allow to reset the realm by passing NULL
X-Git-Tag: samba-4.23.0rc3~18
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3985c45ad97a3b2729f3970a8fbcf989a093ca44;p=thirdparty%2Fsamba.git

auth:creds: Allow to reset the realm by passing NULL

This is e.g. done by cli_credentials_set_anonymous().

We can't call TALLOC_FREE(cred->realm), as this would break
cli_credentials_shallow_copy().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15893

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
(cherry picked from commit e5608cdb2e5a7ef2641ec0e7b0ce0b4640a02ce1)
---

diff --git a/auth/credentials/credentials.c b/auth/credentials/credentials.c
index c31470a81d2..5588a355c74 100644
--- a/auth/credentials/credentials.c
+++ b/auth/credentials/credentials.c
@@ -933,7 +933,14 @@ _PUBLIC_ bool cli_credentials_set_realm(struct cli_credentials *cred,
 			       enum credentials_obtained obtained)
 {
 	if (obtained >= cred->realm_obtained) {
-		cred->realm = strupper_talloc(cred, val);
+		/* If `val = NULL` is passed, realm is reset */
+		cred->realm = NULL;
+		if (val != NULL) {
+			cred->realm = strupper_talloc(cred, val);
+			if (cred->realm == NULL) {
+				return false;
+			}
+		}
 		cred->realm_obtained = obtained;
 		cli_credentials_invalidate_ccache(cred, cred->realm_obtained);
 		return true;