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

This is similar to commit c1609579a421 ("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: 843d93602c1c ("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 ddfc52ac1f9b4391cb8b6e0f107658b1ee011565..c0d323b58e732318cc352be35bf940693b9bd028 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;