Merge tag 'for-net-2025-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth

Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

- L2CAP: Fix L2CAP MTU negotiation
- hci_core: Fix use-after-free in vhci_flush()
- btintel_pcie: Fix potential race condition in firmware download
- hci_qca: fix unable to load the BT driver

* tag 'for-net-2025-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
Bluetooth: hci_core: Fix use-after-free in vhci_flush()
driver: bluetooth: hci_qca:fix unable to load the BT driver
Bluetooth: L2CAP: Fix L2CAP MTU negotiation
Bluetooth: btintel_pcie: Fix potential race condition in firmware download
====================

Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/bluetooth/btintel_pcie.c

···
 	data->hdev = NULL;
 }
 
+static void btintel_pcie_disable_interrupts(struct btintel_pcie_data *data)
+{
+	spin_lock(&data->irq_lock);
+	btintel_pcie_wr_reg32(data, BTINTEL_PCIE_CSR_MSIX_FH_INT_MASK, data->fh_init_mask);
+	btintel_pcie_wr_reg32(data, BTINTEL_PCIE_CSR_MSIX_HW_INT_MASK, data->hw_init_mask);
+	spin_unlock(&data->irq_lock);
+}
+
+static void btintel_pcie_enable_interrupts(struct btintel_pcie_data *data)
+{
+	spin_lock(&data->irq_lock);
+	btintel_pcie_wr_reg32(data, BTINTEL_PCIE_CSR_MSIX_FH_INT_MASK, ~data->fh_init_mask);
+	btintel_pcie_wr_reg32(data, BTINTEL_PCIE_CSR_MSIX_HW_INT_MASK, ~data->hw_init_mask);
+	spin_unlock(&data->irq_lock);
+}
+
+static void btintel_pcie_synchronize_irqs(struct btintel_pcie_data *data)
+{
+	for (int i = 0; i < data->alloc_vecs; i++)
+		synchronize_irq(data->msix_entries[i].vector);
+}
+
 static int btintel_pcie_setup_internal(struct hci_dev *hdev)
 {
 	struct btintel_pcie_data *data = hci_get_drvdata(hdev);
···
 		bt_dev_err(hdev, "Firmware download retry count: %d",
 			   fw_dl_retry);
 		btintel_pcie_dump_debug_registers(hdev);
+		btintel_pcie_disable_interrupts(data);
+		btintel_pcie_synchronize_irqs(data);
 		err = btintel_pcie_reset_bt(data);
 		if (err) {
 			bt_dev_err(hdev, "Failed to do shr reset: %d", err);
···
 		}
 		usleep_range(10000, 12000);
 		btintel_pcie_reset_ia(data);
+		btintel_pcie_enable_interrupts(data);
 		btintel_pcie_config_msix(data);
 		err = btintel_pcie_enable_bt(data);
 		if (err) {
···
 
 	data = pci_get_drvdata(pdev);
 
+	btintel_pcie_disable_interrupts(data);
+
+	btintel_pcie_synchronize_irqs(data);
+
+	flush_work(&data->rx_work);
+
 	btintel_pcie_reset_bt(data);
 	for (int i = 0; i < data->alloc_vecs; i++) {
 		struct msix_entry *msix_entry;
···
 	pci_free_irq_vectors(pdev);
 
 	btintel_pcie_release_hdev(data);
-
-	flush_work(&data->rx_work);
 
 	destroy_workqueue(data->workqueue);
 

drivers/bluetooth/hci_qca.c

···
 			 */
 			qcadev->bt_power->pwrseq = devm_pwrseq_get(&serdev->dev,
 								   "bluetooth");
-			if (IS_ERR(qcadev->bt_power->pwrseq))
-				return PTR_ERR(qcadev->bt_power->pwrseq);
 
-			break;
+			/*
+			 * Some modules have BT_EN enabled via a hardware pull-up,
+			 * meaning it is not defined in the DTS and is not controlled
+			 * through the power sequence. In such cases, fall through
+			 * to follow the legacy flow.
+			 */
+			if (IS_ERR(qcadev->bt_power->pwrseq))
+				qcadev->bt_power->pwrseq = NULL;
+			else
+				break;
 		}
 		fallthrough;
 	case QCA_WCN3950:

include/net/bluetooth/hci_core.h

···
 #include <linux/idr.h>
 #include <linux/leds.h>
 #include <linux/rculist.h>
+#include <linux/srcu.h>
 
 #include <net/bluetooth/hci.h>
 #include <net/bluetooth/hci_drv.h>
···
 
 struct hci_dev {
 	struct list_head list;
+	struct srcu_struct srcu;
 	struct mutex	lock;
 
 	struct ida	unset_handle_ida;

net/bluetooth/hci_core.c

···
 
 /* Get HCI device by index.
  * Device is held on return. */
-struct hci_dev *hci_dev_get(int index)
+static struct hci_dev *__hci_dev_get(int index, int *srcu_index)
 {
 	struct hci_dev *hdev = NULL, *d;
 
···
 	list_for_each_entry(d, &hci_dev_list, list) {
 		if (d->id == index) {
 			hdev = hci_dev_hold(d);
+			if (srcu_index)
+				*srcu_index = srcu_read_lock(&d->srcu);
 			break;
 		}
 	}
 	read_unlock(&hci_dev_list_lock);
 	return hdev;
+}
+
+struct hci_dev *hci_dev_get(int index)
+{
+	return __hci_dev_get(index, NULL);
+}
+
+static struct hci_dev *hci_dev_get_srcu(int index, int *srcu_index)
+{
+	return __hci_dev_get(index, srcu_index);
+}
+
+static void hci_dev_put_srcu(struct hci_dev *hdev, int srcu_index)
+{
+	srcu_read_unlock(&hdev->srcu, srcu_index);
+	hci_dev_put(hdev);
 }
 
 /* ---- Inquiry support ---- */
···
 int hci_dev_reset(__u16 dev)
 {
 	struct hci_dev *hdev;
-	int err;
+	int err, srcu_index;
 
-	hdev = hci_dev_get(dev);
+	hdev = hci_dev_get_srcu(dev, &srcu_index);
 	if (!hdev)
 		return -ENODEV;
 
···
 	err = hci_dev_do_reset(hdev);
 
 done:
-	hci_dev_put(hdev);
+	hci_dev_put_srcu(hdev, srcu_index);
 	return err;
 }
 
···
 	if (!hdev)
 		return NULL;
 
+	if (init_srcu_struct(&hdev->srcu)) {
+		kfree(hdev);
+		return NULL;
+	}
+
 	hdev->pkt_type  = (HCI_DM1 | HCI_DH1 | HCI_HV1);
 	hdev->esco_type = (ESCO_HV1);
 	hdev->link_mode = (HCI_LM_ACCEPT);
···
 	write_lock(&hci_dev_list_lock);
 	list_del(&hdev->list);
 	write_unlock(&hci_dev_list_lock);
+
+	synchronize_srcu(&hdev->srcu);
+	cleanup_srcu_struct(&hdev->srcu);
 
 	disable_work_sync(&hdev->rx_work);
 	disable_work_sync(&hdev->cmd_work);

net/bluetooth/l2cap_core.c

···
 	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
 	struct l2cap_conf_efs efs;
 	u8 remote_efs = 0;
-	u16 mtu = L2CAP_DEFAULT_MTU;
+	u16 mtu = 0;
 	u16 result = L2CAP_CONF_SUCCESS;
 	u16 size;
 
···
 	if (result == L2CAP_CONF_SUCCESS) {
 		/* Configure output options and let the other side know
 		 * which ones we don't like. */
+
+		/* If MTU is not provided in configure request, use the most recently
+		 * explicitly or implicitly accepted value for the other direction,
+		 * or the default value.
+		 */
+		if (mtu == 0)
+			mtu = chan->imtu ? chan->imtu : L2CAP_DEFAULT_MTU;
 
 		if (mtu < L2CAP_DEFAULT_MIN_MTU)
 			result = L2CAP_CONF_UNACCEPT;