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:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH v2 4/5] Bluetooth: hci_conn: Fix modifying handle while aborting
Date:   Thu,  3 Aug 2023 17:11:14 -0700
Message-ID: <20230804001115.907885-4-luiz.dentz@gmail.com>
In-Reply-To: <20230804001115.907885-1-luiz.dentz@gmail.com>
References: <20230804001115.907885-1-luiz.dentz@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This introduces hci_conn_set_handle which takes care of verifying the
conditions where the hci_conn handle can be modified, including when
hci_conn_abort has been called and also checks that the handles is
valid as well.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_conn.c         | 30 ++++++++++++++++++++++++++++++
 net/bluetooth/hci_event.c        | 29 +++++++++++------------------
 3 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 8200a6689b39..d2a3a2a9fd7d 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1425,6 +1425,7 @@ int hci_conn_switch_role(struct hci_conn *conn, __u8 role);
 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active);
 
 void hci_conn_failed(struct hci_conn *conn, u8 status);
+u8 hci_conn_set_handle(struct hci_conn *conn, u16 handle);
 
 /*
  * hci_conn_get() and hci_conn_put() are used to control the life-time of an
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 923bb7e7be2b..13bd2753abbb 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1231,6 +1231,36 @@ void hci_conn_failed(struct hci_conn *conn, u8 status)
 	hci_conn_del(conn);
 }
 
+/* This function requires the caller holds hdev->lock */
+u8 hci_conn_set_handle(struct hci_conn *conn, u16 handle)
+{
+	struct hci_dev *hdev = conn->hdev;
+
+	bt_dev_dbg(hdev, "hcon %p handle 0x%4.4x", conn, handle);
+
+	if (conn->handle == handle)
+		return 0;
+
+	if (handle > HCI_CONN_HANDLE_MAX) {
+		bt_dev_err(hdev, "Invalid handle: 0x%4.4x > 0x%4.4x",
+			   handle, HCI_CONN_HANDLE_MAX);
+		return HCI_ERROR_INVALID_PARAMETERS;
+	}
+
+	/* If abort_reason has been sent it means the connection is being
+	 * aborted and the handle shall not be changed.
+	 */
+	if (conn->abort_reason) {
+		bt_dev_err(hdev, "hcon %p abort_reason 0x%2.2x", conn,
+			   conn->abort_reason);
+		return conn->abort_reason;
+	}
+
+	conn->handle = handle;
+
+	return 0;
+}
+
 static void create_le_conn_complete(struct hci_dev *hdev, void *data, int err)
 {
 	struct hci_conn *conn;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index f1fcece29e7d..218da9b0fe8f 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3179,13 +3179,9 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, void *data,
 	}
 
 	if (!status) {
-		conn->handle = __le16_to_cpu(ev->handle);
-		if (conn->handle > HCI_CONN_HANDLE_MAX) {
-			bt_dev_err(hdev, "Invalid handle: 0x%4.4x > 0x%4.4x",
-				   conn->handle, HCI_CONN_HANDLE_MAX);
-			status = HCI_ERROR_INVALID_PARAMETERS;
+		status = hci_conn_set_handle(conn, __le16_to_cpu(ev->handle));
+		if (status)
 			goto done;
-		}
 
 		if (conn->type == ACL_LINK) {
 			conn->state = BT_CONFIG;
@@ -3849,11 +3845,9 @@ static u8 hci_cc_le_set_cig_params(struct hci_dev *hdev, void *data,
 		if (conn->state != BT_BOUND && conn->state != BT_CONNECT)
 			continue;
 
-		conn->handle = __le16_to_cpu(rp->handle[i]);
+		if (hci_conn_set_handle(conn, __le16_to_cpu(rp->handle[i])))
+			continue;
 
-		bt_dev_dbg(hdev, "%p handle 0x%4.4x parent %p", conn,
-			   conn->handle, conn->parent);
-		
 		if (conn->state == BT_CONNECT)
 			pending = true;
 	}
@@ -5039,11 +5033,8 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, void *data,
 
 	switch (status) {
 	case 0x00:
-		conn->handle = __le16_to_cpu(ev->handle);
-		if (conn->handle > HCI_CONN_HANDLE_MAX) {
-			bt_dev_err(hdev, "Invalid handle: 0x%4.4x > 0x%4.4x",
-				   conn->handle, HCI_CONN_HANDLE_MAX);
-			status = HCI_ERROR_INVALID_PARAMETERS;
+		status = hci_conn_set_handle(conn, __le16_to_cpu(ev->handle));
+		if (status) {
 			conn->state = BT_CLOSED;
 			break;
 		}
@@ -6978,7 +6969,7 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data,
 {
 	struct hci_evt_le_create_big_complete *ev = data;
 	struct hci_conn *conn;
-	__u8 bis_idx = 0;
+	__u8 i = 0;
 
 	BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
 
@@ -6996,7 +6987,9 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data,
 		    conn->iso_qos.bcast.big != ev->handle)
 			continue;
 
-		conn->handle = __le16_to_cpu(ev->bis_handle[bis_idx++]);
+		if (hci_conn_set_handle(conn,
+					__le16_to_cpu(ev->bis_handle[i++])))
+			continue;
 
 		if (!ev->status) {
 			conn->state = BT_CONNECTED;
@@ -7015,7 +7008,7 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data,
 		rcu_read_lock();
 	}
 
-	if (!ev->status && !bis_idx)
+	if (!ev->status && !i)
 		/* If no BISes have been connected for the BIG,
 		 * terminate. This is in case all bound connections
 		 * have been closed before the BIG creation
-- 
2.41.0