Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:46864 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752747AbeDRKFT (ORCPT ); Wed, 18 Apr 2018 06:05:19 -0400 Received: by mail-pf0-f195.google.com with SMTP id h69so660170pfe.13 for ; Wed, 18 Apr 2018 03:05:19 -0700 (PDT) From: Amit Pundir To: lkml , linux-wireless@vger.kernel.org Cc: Samuel Ortiz , Christophe Ricard , Andy Shevchenko , Greg KH , John Stultz , Dmitry Shmidt , Todd Kjos , Android Kernel Team , Suren Baghdasaryan Subject: [RESEND][PATCH 2/4] NFC: st21nfca: Fix memory OOB and leak issues in connectivity events handler Date: Wed, 18 Apr 2018 15:35:02 +0530 Message-Id: <1524045904-7005-3-git-send-email-amit.pundir@linaro.org> (sfid-20180418_120528_277665_17542FE4) In-Reply-To: <1524045904-7005-1-git-send-email-amit.pundir@linaro.org> References: <1524045904-7005-1-git-send-email-amit.pundir@linaro.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Suren Baghdasaryan Overflow on memcpy is possible in kernel driver for st21nfca's NFC HCI layer when handling connectivity events if aid_len or params_len are bigger than the buffer size. Memory leak is possible when parameter tag is invalid. Signed-off-by: Suren Baghdasaryan Signed-off-by: Amit Pundir --- drivers/nfc/st21nfca/se.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c index 4bed9e842db3..acdce231e227 100644 --- a/drivers/nfc/st21nfca/se.c +++ b/drivers/nfc/st21nfca/se.c @@ -322,23 +322,33 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, * AID 81 5 to 16 * PARAMETERS 82 0 to 255 */ - if (skb->len < NFC_MIN_AID_LENGTH + 2 && + if (skb->len < NFC_MIN_AID_LENGTH + 2 || skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG) return -EPROTO; + /* + * Buffer should have enough space for at least + * two tag fields + two length fields + aid_len (skb->data[1]) + */ + if (skb->len < skb->data[1] + 4) + return -EPROTO; + transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev, skb->len - 2, GFP_KERNEL); transaction->aid_len = skb->data[1]; memcpy(transaction->aid, &skb->data[2], transaction->aid_len); + transaction->params_len = skb->data[transaction->aid_len + 3]; - /* Check next byte is PARAMETERS tag (82) */ + /* Check next byte is PARAMETERS tag (82) and the length field */ if (skb->data[transaction->aid_len + 2] != - NFC_EVT_TRANSACTION_PARAMS_TAG) + NFC_EVT_TRANSACTION_PARAMS_TAG || + skb->len < transaction->aid_len + transaction->params_len + 4) { + devm_kfree(dev, transaction); return -EPROTO; + } - transaction->params_len = skb->data[transaction->aid_len + 3]; memcpy(transaction->params, skb->data + transaction->aid_len + 4, transaction->params_len); -- 2.7.4