[PATCH v2 1/3] Bluetooth: qca: add missing firmware sanity checks

[Johan Hovold <johan+linaro@kernel.org>]

Add the missing sanity checks when parsing the firmware files before
downloading them to avoid accessing and corrupting memory beyond the
vmalloced buffer.

Fixes: 83e81961ff7e ("Bluetooth: btqca: Introduce generic QCA ROME support")
Cc: stable@vger.kernel.org	# 4.10
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/bluetooth/btqca.c | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
index cfa71708397b..6743b0a79d7a 100644
--- a/drivers/bluetooth/btqca.c
+++ b/drivers/bluetooth/btqca.c
@@ -268,9 +268,10 @@ int qca_send_pre_shutdown_cmd(struct hci_dev *hdev)
 }
 EXPORT_SYMBOL_GPL(qca_send_pre_shutdown_cmd);
 
-static void qca_tlv_check_data(struct hci_dev *hdev,
+static int qca_tlv_check_data(struct hci_dev *hdev,
 			       struct qca_fw_config *config,
-		u8 *fw_data, enum qca_btsoc_type soc_type)
+			       u8 *fw_data, size_t fw_size,
+			       enum qca_btsoc_type soc_type)
 {
 	const u8 *data;
 	u32 type_len;
@@ -286,6 +287,9 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 
 	switch (config->type) {
 	case ELF_TYPE_PATCH:
+		if (fw_size < 7)
+			return -EINVAL;
+
 		config->dnld_mode = QCA_SKIP_EVT_VSE_CC;
 		config->dnld_type = QCA_SKIP_EVT_VSE_CC;
 
@@ -294,6 +298,9 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 		bt_dev_dbg(hdev, "File version      : 0x%x", fw_data[6]);
 		break;
 	case TLV_TYPE_PATCH:
+		if (fw_size < sizeof(struct tlv_type_hdr) + sizeof(struct tlv_type_patch))
+			return -EINVAL;
+
 		tlv = (struct tlv_type_hdr *)fw_data;
 		type_len = le32_to_cpu(tlv->type_len);
 		tlv_patch = (struct tlv_type_patch *)tlv->data;
@@ -333,6 +340,9 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 		break;
 
 	case TLV_TYPE_NVM:
+		if (fw_size < sizeof(struct tlv_type_hdr))
+			return -EINVAL;
+
 		tlv = (struct tlv_type_hdr *)fw_data;
 
 		type_len = le32_to_cpu(tlv->type_len);
@@ -341,17 +351,26 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 		BT_DBG("TLV Type\t\t : 0x%x", type_len & 0x000000ff);
 		BT_DBG("Length\t\t : %d bytes", length);
 
+		if (fw_size < length + (tlv->data - fw_data))
+			return -EINVAL;
+
 		idx = 0;
 		data = tlv->data;
-		while (idx < length) {
+		while (idx < length - sizeof(struct tlv_type_nvm)) {
 			tlv_nvm = (struct tlv_type_nvm *)(data + idx);
 
 			tag_id = le16_to_cpu(tlv_nvm->tag_id);
 			tag_len = le16_to_cpu(tlv_nvm->tag_len);
 
+			if (length < idx + sizeof(struct tlv_type_nvm) + tag_len)
+				return -EINVAL;
+
 			/* Update NVM tags as needed */
 			switch (tag_id) {
 			case EDL_TAG_ID_HCI:
+				if (tag_len < 3)
+					return -EINVAL;
+
 				/* HCI transport layer parameters
 				 * enabling software inband sleep
 				 * onto controller side.
@@ -367,6 +386,9 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 				break;
 
 			case EDL_TAG_ID_DEEP_SLEEP:
+				if (tag_len < 1)
+					return -EINVAL;
+
 				/* Sleep enable mask
 				 * enabling deep sleep feature on controller.
 				 */
@@ -375,14 +397,16 @@ static void qca_tlv_check_data(struct hci_dev *hdev,
 				break;
 			}
 
-			idx += (sizeof(u16) + sizeof(u16) + 8 + tag_len);
+			idx += sizeof(struct tlv_type_nvm) + tag_len;
 		}
 		break;
 
 	default:
 		BT_ERR("Unknown TLV type %d", config->type);
-		break;
+		return -EINVAL;
 	}
+
+	return 0;
 }
 
 static int qca_tlv_send_segment(struct hci_dev *hdev, int seg_size,
@@ -532,7 +556,9 @@ static int qca_download_firmware(struct hci_dev *hdev,
 	memcpy(data, fw->data, size);
 	release_firmware(fw);
 
-	qca_tlv_check_data(hdev, config, data, soc_type);
+	ret = qca_tlv_check_data(hdev, config, data, size, soc_type);
+	if (ret)
+		return ret;
 
 	segment = data;
 	remain = size;
-- 
2.43.2