Bluetooth: hci_sync: Fix attempting to suspend with unfiltered passive scan

When suspending the passive scanning _must_ have its filter_policy set
to 0x01 to use the accept list otherwise _any_ advertise report would
end up waking up the system.

In order to fix the filter_policy the code now checks for
hdev->suspended && HCI_CONN_FLAG_REMOTE_WAKEUP
first, since the MGMT_OP_SET_DEVICE_FLAGS will reject any attempt to
set HCI_CONN_FLAG_REMOTE_WAKEUP when it cannot be programmed in the
acceptlist, so it can return success causing the proper filter_policy
to be used.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215768
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index a6ada9d..4d2203c 100644 (file)
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -1664,20 +1664,19 @@ static int hci_le_add_accept_list_sync(struct hci_dev *hdev,
        struct hci_cp_le_add_to_accept_list cp;
        int err;
 
+       /* During suspend, only wakeable devices can be in acceptlist */
+       if (hdev->suspended &&
+           !test_bit(HCI_CONN_FLAG_REMOTE_WAKEUP, params->flags))
+               return 0;
+
        /* Select filter policy to accept all advertising */
        if (*num_entries >= hdev->le_accept_list_size)
                return -ENOSPC;
 
        /* Accept list can not be used with RPAs */
        if (!use_ll_privacy(hdev) &&
-           hci_find_irk_by_addr(hdev, &params->addr, params->addr_type)) {
+           hci_find_irk_by_addr(hdev, &params->addr, params->addr_type))
                return -EINVAL;
-       }
-
-       /* During suspend, only wakeable devices can be in acceptlist */
-       if (hdev->suspended &&
-           !test_bit(HCI_CONN_FLAG_REMOTE_WAKEUP, params->flags))
-               return 0;
 
        /* Attempt to program the device in the resolving list first to avoid
         * having to rollback in case it fails since the resolving list is
@@ -4913,10 +4912,28 @@ static int hci_update_event_filter_sync(struct hci_dev *hdev)
        return 0;
 }
 
+/* This function disables scan (BR and LE) and mark it as paused */
+static int hci_pause_scan_sync(struct hci_dev *hdev)
+{
+       if (hdev->scanning_paused)
+               return 0;
+
+       /* Disable page scan if enabled */
+       if (test_bit(HCI_PSCAN, &hdev->flags))
+               hci_write_scan_enable_sync(hdev, SCAN_DISABLED);
+
+       hci_scan_disable_sync(hdev);
+
+       hdev->scanning_paused = true;
+
+       return 0;
+}
+
 /* This function performs the HCI suspend procedures in the follow order:
  *
  * Pause discovery (active scanning/inquiry)
  * Pause Directed Advertising/Advertising
+ * Pause Scanning (passive scanning in case discovery was not active)
  * Disconnect all connections
  * Set suspend_status to BT_SUSPEND_DISCONNECT if hdev cannot wakeup
  * otherwise:
@@ -4942,15 +4959,11 @@ int hci_suspend_sync(struct hci_dev *hdev)
        /* Pause other advertisements */
        hci_pause_advertising_sync(hdev);
 
-       /* Disable page scan if enabled */
-       if (test_bit(HCI_PSCAN, &hdev->flags))
-               hci_write_scan_enable_sync(hdev, SCAN_DISABLED);
-
        /* Suspend monitor filters */
        hci_suspend_monitor_sync(hdev);
 
        /* Prevent disconnects from causing scanning to be re-enabled */
-       hdev->scanning_paused = true;
+       hci_pause_scan_sync(hdev);
 
        /* Soft disconnect everything (power off) */
        err = hci_disconnect_all_sync(hdev, HCI_ERROR_REMOTE_POWER_OFF);
@@ -5021,6 +5034,22 @@ static void hci_resume_monitor_sync(struct hci_dev *hdev)
        }
 }
 
+/* This function resume scan and reset paused flag */
+static int hci_resume_scan_sync(struct hci_dev *hdev)
+{
+       if (!hdev->scanning_paused)
+               return 0;
+
+       hci_update_scan_sync(hdev);
+
+       /* Reset passive scanning to normal */
+       hci_update_passive_scan_sync(hdev);
+
+       hdev->scanning_paused = false;
+
+       return 0;
+}
+
 /* This function performs the HCI suspend procedures in the follow order:
  *
  * Restore event mask
@@ -5043,10 +5072,9 @@ int hci_resume_sync(struct hci_dev *hdev)
 
        /* Clear any event filters and restore scan state */
        hci_clear_event_filter_sync(hdev);
-       hci_update_scan_sync(hdev);
 
-       /* Reset passive scanning to normal */
-       hci_update_passive_scan_sync(hdev);
+       /* Resume scanning */
+       hci_resume_scan_sync(hdev);
 
        /* Resume monitor filters */
        hci_resume_monitor_sync(hdev);