NFC: nci: Add some bounds checking in nci_hci_cmd_received()

This is similar to commit 674d9de02aa7 ("NFC: Fix possible memory
corruption when handling SHDLC I-Frame commands").

I'm not totally sure, but I think that commit description may have
overstated the danger.  I was under the impression that this data came
from the firmware?  If you can't trust your networking firmware, then
you're already in trouble.

Anyway, these days we add bounds checking where ever we can and we call
it kernel hardening.  Better safe than sorry.

Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index ddfc52a..c0d323b 100644 (file)
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -312,6 +312,10 @@ static void nci_hci_cmd_received(struct nci_dev *ndev, u8 pipe,
                create_info = (struct nci_hci_create_pipe_resp *)skb->data;
                dest_gate = create_info->dest_gate;
                new_pipe = create_info->pipe;
+               if (new_pipe >= NCI_HCI_MAX_PIPES) {
+                       status = NCI_HCI_ANY_E_NOK;
+                       goto exit;
+               }
 
                /* Save the new created pipe and bind with local gate,
                 * the description for skb->data[3] is destination gate id
@@ -336,6 +340,10 @@ static void nci_hci_cmd_received(struct nci_dev *ndev, u8 pipe,
                        goto exit;
                }
                delete_info = (struct nci_hci_delete_pipe_noti *)skb->data;
+               if (delete_info->pipe >= NCI_HCI_MAX_PIPES) {
+                       status = NCI_HCI_ANY_E_NOK;
+                       goto exit;
+               }
 
                ndev->hci_dev->pipes[delete_info->pipe].gate =
                                                NCI_HCI_INVALID_GATE;