Bluetooth: MGMT: Fix possible crash on mgmt_index_removed

If mgmt_index_removed is called while there are commands queued on
cmd_sync it could lead to crashes like the bellow trace:

0x0000053D: __list_del_entry_valid_or_report+0x98/0xdc
0x0000053D: mgmt_pending_remove+0x18/0x58 [bluetooth]
0x0000053E: mgmt_remove_adv_monitor_complete+0x80/0x108 [bluetooth]
0x0000053E: hci_cmd_sync_work+0xbc/0x164 [bluetooth]

So while handling mgmt_index_removed this attempts to dequeue
commands passed as user_data to cmd_sync.

Fixes: 7cf5c2978f23 ("Bluetooth: hci_sync: Refactor remove Adv Monitor")
Reported-by: jiaymao <quic_jiaymao@quicinc.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index e4f564d6f6fbfb8ed659e025b2498c249d1667b3..4157d9f23f46ef6e8bb716462ec1edc5de078f0d 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1453,10 +1453,15 @@ static void cmd_status_rsp(struct mgmt_pending_cmd *cmd, void *data)
 
 static void cmd_complete_rsp(struct mgmt_pending_cmd *cmd, void *data)
 {
-       if (cmd->cmd_complete) {
-               u8 *status = data;
+       struct cmd_lookup *match = data;
+
+       /* dequeue cmd_sync entries using cmd as data as that is about to be
+        * removed/freed.
+        */
+       hci_cmd_sync_dequeue(match->hdev, NULL, cmd, NULL);
 
-               cmd->cmd_complete(cmd, *status);
+       if (cmd->cmd_complete) {
+               cmd->cmd_complete(cmd, match->mgmt_status);
                mgmt_pending_remove(cmd);
 
                return;
@@ -9394,12 +9399,12 @@ void mgmt_index_added(struct hci_dev *hdev)
 void mgmt_index_removed(struct hci_dev *hdev)
 {
        struct mgmt_ev_ext_index ev;
-       u8 status = MGMT_STATUS_INVALID_INDEX;
+       struct cmd_lookup match = { NULL, hdev, MGMT_STATUS_INVALID_INDEX };
 
        if (test_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks))
                return;
 
-       mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &status);
+       mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &match);
 
        if (hci_dev_test_flag(hdev, HCI_UNCONFIGURED)) {
                mgmt_index_event(MGMT_EV_UNCONF_INDEX_REMOVED, hdev, NULL, 0,
@@ -9450,7 +9455,7 @@ void mgmt_power_on(struct hci_dev *hdev, int err)
 void __mgmt_power_off(struct hci_dev *hdev)
 {
        struct cmd_lookup match = { NULL, hdev };
-       u8 status, zero_cod[] = { 0, 0, 0 };
+       u8 zero_cod[] = { 0, 0, 0 };
 
        mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, settings_rsp, &match);
 
@@ -9462,11 +9467,11 @@ void __mgmt_power_off(struct hci_dev *hdev)
         * status responses.
         */
        if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
-               status = MGMT_STATUS_INVALID_INDEX;
+               match.mgmt_status = MGMT_STATUS_INVALID_INDEX;
        else
-               status = MGMT_STATUS_NOT_POWERED;
+               match.mgmt_status = MGMT_STATUS_NOT_POWERED;
 
-       mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &status);
+       mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &match);
 
        if (memcmp(hdev->dev_class, zero_cod, sizeof(zero_cod)) != 0) {
                mgmt_limited_event(MGMT_EV_CLASS_OF_DEV_CHANGED, hdev,