[PATCH 6.1 236/303] Bluetooth: hci_sync: Introduce hci_cmd_sync_run/hci_cmd_sync_run_once

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Luiz Augusto von Dentz <[email protected]>

[ Upstream commit c898f6d7b093bd71e66569cd6797c87d4056f44b ]

This introduces hci_cmd_sync_run/hci_cmd_sync_run_once which acts like
hci_cmd_sync_queue/hci_cmd_sync_queue_once but runs immediately when
already on hdev->cmd_sync_work context.

Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Stable-dep-of: d0a7b48ad092 ("Bluetooth: mgmt: fix UAF in pair command cancellation")
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 include/net/bluetooth/hci_sync.h |    4 +++
 net/bluetooth/hci_sync.c         |   42 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 44 insertions(+), 2 deletions(-)

--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -69,6 +69,10 @@ hci_cmd_sync_lookup_entry(struct hci_dev
 			  void *data, hci_cmd_sync_work_destroy_t destroy);
 int hci_cmd_sync_queue_once(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 			    void *data, hci_cmd_sync_work_destroy_t destroy);
+int hci_cmd_sync_run(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+		     void *data, hci_cmd_sync_work_destroy_t destroy);
+int hci_cmd_sync_run_once(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy);
 void hci_cmd_sync_cancel_entry(struct hci_dev *hdev,
 			       struct hci_cmd_sync_work_entry *entry);
 bool hci_cmd_sync_dequeue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -108,7 +108,7 @@ static void hci_cmd_sync_add(struct hci_
 	skb_queue_tail(&req->cmd_q, skb);
 }
 
-static int hci_cmd_sync_run(struct hci_request *req)
+static int hci_req_sync_run(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;
 	struct sk_buff *skb;
@@ -165,7 +165,7 @@ struct sk_buff *__hci_cmd_sync_sk(struct
 
 	hdev->req_status = HCI_REQ_PEND;
 
-	err = hci_cmd_sync_run(&req);
+	err = hci_req_sync_run(&req);
 	if (err < 0)
 		return ERR_PTR(err);
 
@@ -805,6 +805,44 @@ int hci_cmd_sync_queue_once(struct hci_d
 }
 EXPORT_SYMBOL(hci_cmd_sync_queue_once);
 
+/* Run HCI command:
+ *
+ * - hdev must be running
+ * - if on cmd_sync_work then run immediately otherwise queue
+ */
+int hci_cmd_sync_run(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+		     void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	/* Only queue command if hdev is running which means it had been opened
+	 * and is either on init phase or is already up.
+	 */
+	if (!test_bit(HCI_RUNNING, &hdev->flags))
+		return -ENETDOWN;
+
+	/* If on cmd_sync_work then run immediately otherwise queue */
+	if (current_work() == &hdev->cmd_sync_work)
+		return func(hdev, data);
+
+	return hci_cmd_sync_submit(hdev, func, data, destroy);
+}
+EXPORT_SYMBOL(hci_cmd_sync_run);
+
+/* Run HCI command entry once:
+ *
+ * - Lookup if an entry already exist and only if it doesn't creates a new entry
+ *   and run it.
+ * - if on cmd_sync_work then run immediately otherwise queue
+ */
+int hci_cmd_sync_run_once(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	if (hci_cmd_sync_lookup_entry(hdev, func, data, destroy))
+		return 0;
+
+	return hci_cmd_sync_run(hdev, func, data, destroy);
+}
+EXPORT_SYMBOL(hci_cmd_sync_run_once);
+
 /* Lookup HCI command entry:
  *
  * - Return first entry that matches by function callback or data or