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Subject[PATCH 5.17 133/298] Bluetooth: hci_sync: Fix attempting to suspend with unfiltered passive scan
Date
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

[ Upstream commit 3b42055388c30f2761a2d9cd9af2c99611dfe457 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/hci_sync.c | 58 +++++++++++++++++++++++++++++-----------
1 file changed, 43 insertions(+), 15 deletions(-)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 13600bf120b0..6b8d1cd65de4 100644
--- 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
@@ -4881,10 +4880,28 @@ 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:
@@ -4910,15 +4927,11 @@ 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);
@@ -4989,6 +5002,22 @@ 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
@@ -5011,10 +5040,9 @@ 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);
--
2.35.1


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