From: Suren Baghdasaryan surenb@google.com
When handling SHDLC I-Frame commands "pipe" field used for indexing into an array should be checked before usage. If left unchecked it might access memory outside of the array of size NFC_HCI_MAX_PIPES(127).
Malformed NFC HCI frames could be injected by a malicious NFC device communicating with the device being attacked (remote attack vector), or even by an attacker with physical access to the I2C bus such that they could influence the data transfers on that bus (local attack vector). skb->data is controlled by the attacker and has only been sanitized in the most trivial ways (CRC check), therefore we can consider the create_info struct and all of its members to tainted. 'create_info->pipe' with max value of 255 (uint8) is used to take an offset of the hdev->pipes array of 127 elements which can lead to OOB write.
Cc: Samuel Ortiz sameo@linux.intel.com Cc: Allen Pais allen.pais@oracle.com Cc: "David S. Miller" davem@davemloft.net Suggested-by: Kevin Deus kdeus@google.com Signed-off-by: Suren Baghdasaryan surenb@google.com Acked-by: Kees Cook keescook@chromium.org Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/nfc/hci/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c index ac8030c4bcf8..19cb2e473ea6 100644 --- a/net/nfc/hci/core.c +++ b/net/nfc/hci/core.c @@ -209,6 +209,11 @@ void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd, } create_info = (struct hci_create_pipe_resp *)skb->data;
+ if (create_info->pipe >= NFC_HCI_MAX_PIPES) { + status = NFC_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 * but since we received this cmd from host controller, we @@ -232,6 +237,11 @@ void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd, } delete_info = (struct hci_delete_pipe_noti *)skb->data;
+ if (delete_info->pipe >= NFC_HCI_MAX_PIPES) { + status = NFC_HCI_ANY_E_NOK; + goto exit; + } + hdev->pipes[delete_info->pipe].gate = NFC_HCI_INVALID_GATE; hdev->pipes[delete_info->pipe].dest_host = NFC_HCI_INVALID_HOST; break;