Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65E6FC433EF for ; Wed, 17 Nov 2021 17:16:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B08961B3A for ; Wed, 17 Nov 2021 17:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233407AbhKQRTg (ORCPT ); Wed, 17 Nov 2021 12:19:36 -0500 Received: from h4.fbrelay.privateemail.com ([131.153.2.45]:33104 "EHLO h4.fbrelay.privateemail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229585AbhKQRTd (ORCPT ); Wed, 17 Nov 2021 12:19:33 -0500 Received: from MTA-13-4.privateemail.com (mta-13-1.privateemail.com [198.54.122.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by h3.fbrelay.privateemail.com (Postfix) with ESMTPS id C302F80BFE; Wed, 17 Nov 2021 12:16:31 -0500 (EST) Received: from mta-13.privateemail.com (localhost [127.0.0.1]) by mta-13.privateemail.com (Postfix) with ESMTP id E888518000A1; Wed, 17 Nov 2021 12:16:29 -0500 (EST) Received: from localhost.localdomain (unknown [10.20.151.211]) by mta-13.privateemail.com (Postfix) with ESMTPA id 0322F18000A8; Wed, 17 Nov 2021 12:16:27 -0500 (EST) From: Jordy Zomer To: linux-kernel@vger.kernel.org Cc: Jordy Zomer , Krzysztof Kozlowski , Jakub Kicinski , "David S. Miller" , wengjianfeng , netdev@vger.kernel.org Subject: [PATCH] nfc: st-nci: Fix potential buffer overflows in EVT_TRANSACTION Date: Wed, 17 Nov 2021 18:15:51 +0100 Message-Id: <20211117171554.2731340-1-jordy@pwning.systems> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It appears that there are some buffer overflows in EVT_TRANSACTION. This happens because the length parameters that are passed to memcpy come directly from skb->data and are not guarded in any way. It would be nice if someone can review and test this patch because I don't own the hardware :) Signed-off-by: Jordy Zomer --- drivers/nfc/st-nci/se.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/nfc/st-nci/se.c b/drivers/nfc/st-nci/se.c index 7764b1a4c3cf..0d22853925d8 100644 --- a/drivers/nfc/st-nci/se.c +++ b/drivers/nfc/st-nci/se.c @@ -335,6 +335,12 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, return -ENOMEM; transaction->aid_len = skb->data[1]; + + // Checking if the length of the AID is valid + if (transaction->aid_len > sizeof(transaction->aid)) + return -EINVAL; + + memcpy(transaction->aid, &skb->data[2], transaction->aid_len); /* Check next byte is PARAMETERS tag (82) */ @@ -343,6 +349,15 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, return -EPROTO; transaction->params_len = skb->data[transaction->aid_len + 3]; + + // check if the length of the parameters is valid + // we can't use sizeof(transaction->params) because it's + // a flexible array member so we have to check if params_len + // is bigger than the space allocated for the array + if (transaction->params_len > ((skb->len - 2) - sizeof(struct nfc_evt_transaction))) + return -EINVAL; + + memcpy(transaction->params, skb->data + transaction->aid_len + 4, transaction->params_len); -- 2.27.0