Bluetooth: hci_qca: Bug fix during SSR timeout

Due to race conditions between qca_hw_error and qca_controller_memdump
during SSR timeout,the same pointer is freed twice. This results in a
double free. Now a lock is acquired before checking the stauts of SSR
state.

Fixes: d841502c79e3 ("Bluetooth: hci_qca: Collect controller memory dump during SSR")
Signed-off-by: Venkata Lakshmi Narayana Gubba <gubbaven@codeaurora.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 28c34a1..f3fde99 100644 (file)
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -981,8 +981,11 @@ static void qca_controller_memdump(struct work_struct *work)
        while ((skb = skb_dequeue(&qca->rx_memdump_q))) {
 
                mutex_lock(&qca->hci_memdump_lock);
-               /* Skip processing the received packets if timeout detected. */
-               if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT) {
+               /* Skip processing the received packets if timeout detected
+                * or memdump collection completed.
+                */
+               if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT ||
+                   qca->memdump_state == QCA_MEMDUMP_COLLECTED) {
                        mutex_unlock(&qca->hci_memdump_lock);
                        return;
                }
@@ -1483,8 +1486,6 @@ static void qca_hw_error(struct hci_dev *hdev, u8 code)
 {
        struct hci_uart *hu = hci_get_drvdata(hdev);
        struct qca_data *qca = hu->priv;
-       struct qca_memdump_data *qca_memdump = qca->qca_memdump;
-       char *memdump_buf = NULL;
 
        set_bit(QCA_HW_ERROR_EVENT, &qca->flags);
        bt_dev_info(hdev, "mem_dump_status: %d", qca->memdump_state);
@@ -1507,19 +1508,23 @@ static void qca_hw_error(struct hci_dev *hdev, u8 code)
                qca_wait_for_dump_collection(hdev);
        }
 
+       mutex_lock(&qca->hci_memdump_lock);
        if (qca->memdump_state != QCA_MEMDUMP_COLLECTED) {
                bt_dev_err(hu->hdev, "clearing allocated memory due to memdump timeout");
-               mutex_lock(&qca->hci_memdump_lock);
-               if (qca_memdump)
-                       memdump_buf = qca_memdump->memdump_buf_head;
-               vfree(memdump_buf);
-               kfree(qca_memdump);
-               qca->qca_memdump = NULL;
+               if (qca->qca_memdump) {
+                       vfree(qca->qca_memdump->memdump_buf_head);
+                       kfree(qca->qca_memdump);
+                       qca->qca_memdump = NULL;
+               }
                qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
                cancel_delayed_work(&qca->ctrl_memdump_timeout);
-               skb_queue_purge(&qca->rx_memdump_q);
-               mutex_unlock(&qca->hci_memdump_lock);
+       }
+       mutex_unlock(&qca->hci_memdump_lock);
+
+       if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT ||
+           qca->memdump_state == QCA_MEMDUMP_COLLECTED) {
                cancel_work_sync(&qca->ctrl_memdump_evt);
+               skb_queue_purge(&qca->rx_memdump_q);
        }
 
        clear_bit(QCA_HW_ERROR_EVENT, &qca->flags);