[PATCH] Bluetooth: hci_nokia: validate firmware packet bounds

[Pengpeng Hou]

nokia_setup_fw() walks a length-prefixed firmware stream and
decodes HCI command packets from each record.

Check that each record fits in the remaining firmware image, that command
records contain the HCI command header, and that the payload length is
covered before submitting the command.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
 drivers/bluetooth/hci_nokia.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/bluetooth/hci_nokia.c b/drivers/bluetooth/hci_nokia.c
index 1e65b541f8ad..be2923231e71 100644
--- a/drivers/bluetooth/hci_nokia.c
+++ b/drivers/bluetooth/hci_nokia.c
@@ -354,9 +354,29 @@ static int nokia_setup_fw(struct hci_uart *hu)
 		u16 opcode;
 		struct sk_buff *skb;
 
+		if (pkt_size > fw_size - 2) {
+			err = -EINVAL;
+			dev_err(dev, "%s: Malformed firmware packet\n",
+				hu->hdev->name);
+			goto done;
+		}
+
 		switch (pkt_type) {
 		case HCI_COMMAND_PKT:
+			if (pkt_size < 1 + HCI_COMMAND_HDR_SIZE) {
+				err = -EINVAL;
+				dev_err(dev, "%s: Malformed firmware command\n",
+					hu->hdev->name);
+				goto done;
+			}
+
 			cmd = (struct hci_command_hdr *)(fw_ptr + 3);
+			if (cmd->plen > pkt_size - 1 - HCI_COMMAND_HDR_SIZE) {
+				err = -EINVAL;
+				dev_err(dev, "%s: Truncated firmware command\n",
+					hu->hdev->name);
+				goto done;
+			}
 			opcode = le16_to_cpu(cmd->opcode);
 
 			skb = __hci_cmd_sync(hu->hdev, opcode, cmd->plen,
-- 
2.43.0