Bluetooth: hci_sync: Fix attempting to suspend with unfiltered passiv…

…e 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>

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);