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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH v2] Bluetooth: MGMT: Fix helding hci_conn reference while command is queued
Date:   Thu, 21 Jul 2022 17:26:00 -0700
Message-Id: <20220722002600.632792-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This removes the use of hci_conn_hold from Get Conn Info and Get Clock
Info since the callback can just do a lookup by address using the cmd
data and only then set cmd->user_data to pass to the complete callback.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
v2: Fix CI findings

 net/bluetooth/mgmt.c | 51 +++++++++++---------------------------------
 1 file changed, 12 insertions(+), 39 deletions(-)

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 0c6878095709..aa651129b714 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -6711,11 +6711,6 @@ static void get_conn_info_complete(struct hci_dev *hdev, void *data, int err)
 	mgmt_cmd_complete(cmd->sk, cmd->index, MGMT_OP_GET_CONN_INFO, status,
 			  &rp, sizeof(rp));
 
-	if (conn) {
-		hci_conn_drop(conn);
-		hci_conn_put(conn);
-	}
-
 	mgmt_pending_free(cmd);
 }
 
@@ -6734,15 +6729,10 @@ static int get_conn_info_sync(struct hci_dev *hdev, void *data)
 	else
 		conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, &cp->addr.bdaddr);
 
-	if (!conn || conn != cmd->user_data || conn->state != BT_CONNECTED) {
-		if (cmd->user_data) {
-			hci_conn_drop(cmd->user_data);
-			hci_conn_put(cmd->user_data);
-			cmd->user_data = NULL;
-		}
+	if (!conn || conn->state != BT_CONNECTED)
 		return MGMT_STATUS_NOT_CONNECTED;
-	}
 
+	cmd->user_data = conn;
 	handle = cpu_to_le16(conn->handle);
 
 	/* Refresh RSSI each time */
@@ -6824,8 +6814,6 @@ static int get_conn_info(struct sock *sk, struct hci_dev *hdev, void *data,
 		if (!cmd) {
 			err = -ENOMEM;
 		} else {
-			hci_conn_hold(conn);
-			cmd->user_data = hci_conn_get(conn);
 			err = hci_cmd_sync_queue(hdev, get_conn_info_sync,
 						 cmd, get_conn_info_complete);
 		}
@@ -6878,8 +6866,6 @@ static void get_clock_info_complete(struct hci_dev *hdev, void *data, int err)
 	if (conn) {
 		rp.piconet_clock = cpu_to_le32(conn->clock);
 		rp.accuracy = cpu_to_le16(conn->clock_accuracy);
-		hci_conn_drop(conn);
-		hci_conn_put(conn);
 	}
 
 complete:
@@ -6894,30 +6880,21 @@ static int get_clock_info_sync(struct hci_dev *hdev, void *data)
 	struct mgmt_pending_cmd *cmd = data;
 	struct mgmt_cp_get_clock_info *cp = cmd->param;
 	struct hci_cp_read_clock hci_cp;
-	struct hci_conn *conn = cmd->user_data;
-	int err;
+	struct hci_conn *conn;
 
 	memset(&hci_cp, 0, sizeof(hci_cp));
-	err = hci_read_clock_sync(hdev, &hci_cp);
+	hci_read_clock_sync(hdev, &hci_cp);
 
-	if (conn) {
-		/* Make sure connection still exists */
-		conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK,
-					       &cp->addr.bdaddr);
+	/* Make sure connection still exists */
+	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &cp->addr.bdaddr);
+	if (!conn || conn->state != BT_CONNECTED)
+		return MGMT_STATUS_NOT_CONNECTED;
 
-		if (conn && conn == cmd->user_data &&
-		    conn->state == BT_CONNECTED) {
-			hci_cp.handle = cpu_to_le16(conn->handle);
-			hci_cp.which = 0x01; /* Piconet clock */
-			err = hci_read_clock_sync(hdev, &hci_cp);
-		} else if (cmd->user_data) {
-			hci_conn_drop(cmd->user_data);
-			hci_conn_put(cmd->user_data);
-			cmd->user_data = NULL;
-		}
-	}
+	cmd->user_data = conn;
+	hci_cp.handle = cpu_to_le16(conn->handle);
+	hci_cp.which = 0x01; /* Piconet clock */
 
-	return err;
+	return hci_read_clock_sync(hdev, &hci_cp);
 }
 
 static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
@@ -6976,10 +6953,6 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
 
 		if (cmd)
 			mgmt_pending_free(cmd);
-
-	} else if (conn) {
-		hci_conn_hold(conn);
-		cmd->user_data = hci_conn_get(conn);
 	}
 
 
-- 
2.36.1