cifs: set domainName when a domain-key is used in multiuser

RHBZ: 1710429

When we use a domain-key to authenticate using multiuser we must also set
the domainnmame for the new volume as it will be used and passed to the server
in the NTLMSSP Domain-name.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/connect.c

@@ -2981,6 +2981,7 @@ static int
 cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
 {
 	int rc = 0;
+	int is_domain = 0;
 	const char *delim, *payload;
 	char *desc;
 	ssize_t len;
@@ -3028,6 +3029,7 @@ cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
 			rc = PTR_ERR(key);
 			goto out_err;
 		}
+		is_domain = 1;
 	}
 
 	down_read(&key->sem);
@@ -3085,6 +3087,26 @@ cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
 		goto out_key_put;
 	}
 
+	/*
+	 * If we have a domain key then we must set the domainName in the
+	 * for the request.
+	 */
+	if (is_domain && ses->domainName) {
+		vol->domainname = kstrndup(ses->domainName,
+					   strlen(ses->domainName),
+					   GFP_KERNEL);
+		if (!vol->domainname) {
+			cifs_dbg(FYI, "Unable to allocate %zd bytes for "
+				 "domain\n", len);
+			rc = -ENOMEM;
+			kfree(vol->username);
+			vol->username = NULL;
+			kfree(vol->password);
+			vol->password = NULL;
+			goto out_key_put;
+		}
+	}
+
 out_key_put:
 	up_read(&key->sem);
 	key_put(key);