Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Vlad Pruteanu <vlad.pruteanu@nxp.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     claudia.rosu@nxp.com, mihai-octavian.urzica@nxp.com,
        silviu.barbulescu@nxp.com, iulia.tanasescu@nxp.com,
        andrei.istodorescu@nxp.com, Vlad Pruteanu <vlad.pruteanu@nxp.com>
Subject: [PATCH BlueZ 1/1] plugins/admin: Fix heap-use-after-free when using 2 controllers
Date:   Tue,  4 Jul 2023 08:56:43 +0300
Message-Id: <20230704055643.296260-2-vlad.pruteanu@nxp.com>
In-Reply-To: <20230704055643.296260-1-vlad.pruteanu@nxp.com>
References: <20230704055643.296260-1-vlad.pruteanu@nxp.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Kc2VDc5lnFqCAd/TtqmH1YtUeFkzDp5x1FXJnqEMY6SDFcQ3HU2raWvknhrp?=
 =?us-ascii?Q?OF1o6NBllkA1Wt7F279vD2o8CpkBb0jbCulW+kv9aMa9npG8iExowRFLu/3J?=
 =?us-ascii?Q?m4TZxPtmSW3t4A9CznQEDM8I8ddbxmvusvQRYeWSw7USBaJkXGTtHJSZXNGR?=
 =?us-ascii?Q?vk1zNBozs8XFWO6zpC6Vww+rZdKapkcimuiXSU0asrUBi+lQoarXbU7dfeXS?=
 =?us-ascii?Q?cIilkUms6bcR4FV26pxE1rYI0HUqnrt56KWNsaidVOffHRXmRENTFc1MxvRF?=
 =?us-ascii?Q?EO2ml69Je/9Y4LIjXQrQQFobJgRRwuoSxhT4p9Uy2GXa7T3NymZu8Tk7d8h2?=
 =?us-ascii?Q?Yj42BTWRPCME4xD6P/tbOnyPOhUXqTtbCLFe25no1ZF1jjdOG3xjl+BfTauP?=
 =?us-ascii?Q?aaLKc0fDLZ529IAQhbDCNrQL/726yb5OCLIKrugYib4e5UVqW4PaLqrWHNnd?=
 =?us-ascii?Q?CCWMFhFWzwIFCuelqqIP0HU8FtM7NfJY3c+mv8JifPikwnSN3KtfUL+Y04Cg?=
 =?us-ascii?Q?3GKFe3Zks+TGtYyY9KbztPZjYorzslNTcDltgOX4HFkwJx5kdID0bjjurp84?=
 =?us-ascii?Q?O/l+vTQ948Xwq8Mlopo4n87Bqd2pvfssboEmm0s+nSe6Zh/ilPCwG/2S9mVB?=
 =?us-ascii?Q?4FA+uVhSct+gX1QoO+mR1HZyfgg73IX0SecPo0hABoTXcrvGurJbbyQK7zQZ?=
 =?us-ascii?Q?w5J61R0NIC2oeCKtl3kfS6IewwMbts1MgzEo83vhg1pqrxmi/hVzHgBUeVvM?=
 =?us-ascii?Q?0QVarBSs7wFwHDEbeso79RNjWfNtRa3eE65fPjLeAGZ84ElvAq7SYCiuN/cW?=
 =?us-ascii?Q?GwVylJH6hbysXDYufT0IxnofGJ6nYjkPjw0HOuiI8FoYE8sA0GyMiL98iKjZ?=
 =?us-ascii?Q?7cyOllYORJmhQha0QirU6mtcV6f7Ele9nmSzmYWcwXjYU6h3mCvh3DLLqh4f?=
 =?us-ascii?Q?iZo0IkcnWPXl0zurMQZtd6TTL73sHOmXfhgE2XD0bZ8RYEmQF2DPvDcs+U86?=
 =?us-ascii?Q?EDjjxF7k1z/ZJyG+8cMqFv45lPxcgVuKYr6q0FsGYcpfJPXAnxk7rG6hvhd4?=
 =?us-ascii?Q?FH9DRdTWI/LZYx6NnRF/+k8n+/yH/wdGhEtJEOX1wGtPRAAmKFrYZLF0LRfb?=
 =?us-ascii?Q?ljX964AUk7+3xvHrBPRgi7PFeFjfor3d86yeLYQAhObF/latBHaOXgbtIVAJ?=
 =?us-ascii?Q?UYC+0RR1dHETkgpk2tOFKkKU6sL8R6Xo0CbKHSybH6MZIHDLW7On0EZYkOKg?=
 =?us-ascii?Q?lFLQydBJw0gS0lxvmlczXVf44tC+pwXQloKjjlrnZOaPIqG2qxXToHriFQd5?=
 =?us-ascii?Q?1aN21YCm4aFkqYdXi1CPiY/7bJIkrzAJP8PP05w3U0YKH5N3EHsiMyzrkWxS?=
 =?us-ascii?Q?tcO4GNFmaeW12QB0UEGoJ1hDInDQxBXrjvnpXz++9lojes1MGAb6I2LdLeVQ?=
 =?us-ascii?Q?fUW9kcMQt/5qFmtO79XEKZkz6JKwlDlI6h4plMsS9i/Wrraf0yivrLhsbBLx?=
 =?us-ascii?Q?DpWBZ3K3Iwub1fxCmI1jHnLdedZivrqFX9efcPXNtNETC7JqOnrbujfOqceU?=
 =?us-ascii?Q?GiIk/n2IO44IkPDs8iBpgDGqY7QB8Cf0U0HRlEnyCIImSYZtgeaPcJaEUT4m?=
 =?us-ascii?Q?Uw=3D=3D?=
X-OriginatorOrg: nxp.com
X-MS-Exchange-CrossTenant-Network-Message-Id: a19e02da-4feb-443e-7227-08db7c543408
X-MS-Exchange-CrossTenant-AuthSource: DB6PR0402MB2919.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Jul 2023 06:02:09.6959
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: psuLLff/ZL/xcsOGodhsg87TuaYwwYPotFgGh1wMfHiMdHhH/pQtJletLmhYkztPKnDswpsU+6WKmHqQBHI24g==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PR3PR04MB7452
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,
        URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-bluetooth.vger.kernel.org>
X-Mailing-List: linux-bluetooth@vger.kernel.org

This commit fixes the heap-use-after-free error when connecting 2
controllers. When a controller is connected
admin_policy_adapter_probe is called. If policy_data was already
allocated it gets freed, if not, it only gets allocated. Eventually
add_interface is called. Here policy_data is put in the "data" variable
(specific for each controller) and the process_changes task is called
with idle priority. This function ultimately accesses policy_data from
the "data" variable.

When Bluez crashes the flow is:
1)first controller is attached
2)admin_policy_adapter_probe is called and policy_data is allocated
4)second controller is attached
5)admin_policy_adapter_probe is called and policy_data is freed, then
allocated again
6)process_changes runs and the policy_data for the first controller is
read, but it was already freed, thus the crash

---
 plugins/admin.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/plugins/admin.c b/plugins/admin.c
index 68e9237d3..16b74cfbf 100644
--- a/plugins/admin.c
+++ b/plugins/admin.c
@@ -502,7 +502,6 @@ static int admin_policy_adapter_probe(struct btd_adapter *adapter)
 	if (policy_data) {
 		btd_warn(policy_data->adapter_id,
 						"Policy data already exists");
-		admin_policy_free(policy_data);
 		policy_data = NULL;
 	}
 
-- 
2.34.1