NFC: Fix the number of pipes

surenbaghdasaryan · davem330 · commit e285d5bfb7e9 · 2018-09-18T19:55:01.000-07:00
According to ETSI TS 102 622 specification chapter 4.4 pipe identifier
is 7 bits long which allows for 128 unique pipe IDs. Because
NFC_HCI_MAX_PIPES is used as the number of pipes supported and not
as the max pipe ID, its value should be 128 instead of 127.

nfc_hci_recv_from_llc extracts pipe ID from packet header using
NFC_HCI_FRAGMENT(0x7F) mask which allows for pipe ID value of 127.
Same happens when NCI_HCP_MSG_GET_PIPE() is being used. With
pipes array having only 127 elements and pipe ID of 127 the OOB memory
access will result.

Cc: Samuel Ortiz &lt;sameo@linux.intel.com&gt;
Cc: Allen Pais &lt;allen.pais@oracle.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Suggested-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/include/net/nfc/hci.h b/include/net/nfc/hci.h
@@ -87,7 +87,7 @@ struct nfc_hci_pipe {
  * According to specification 102 622 chapter 4.4 Pipes,
  * the pipe identifier is 7 bits long.
  */
-#define NFC_HCI_MAX_PIPES		127
+#define NFC_HCI_MAX_PIPES		128
 struct nfc_hci_init_data {
 	u8 gate_count;
 	struct nfc_hci_gate gates[NFC_HCI_MAX_CUSTOM_GATES];
