Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760137Ab2FUT4R (ORCPT ); Thu, 21 Jun 2012 15:56:17 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:53127 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759914Ab2FUT4Q (ORCPT ); Thu, 21 Jun 2012 15:56:16 -0400 Message-ID: <4FE37C5C.4090009@gmail.com> Date: Thu, 21 Jun 2012 15:56:12 -0400 From: Dan Rosenberg User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: lauro.venancio@openbossa.org, aloisio.almeida@openbossa.org, sameo@linux.intel.com, David Miller , ilane@ti.com CC: linux-kernel@vger.kernel.org, security@kernel.org, linux-netdev@vger.kernel.org Subject: [PATCH] NFC: prevent multiple buffer overflows in NCI X-Enigmail-Version: 1.5pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3299 Lines: 77 Fix multiple remotely-exploitable stack-based buffer overflows due to the NCI code pulling length fields directly from incoming frames and copying too much data into statically-sized arrays. Fortunately, there don't appear to be any active users of this code (yet). This patch fixes the overflows, but I suspect the code will need to be completely reworked since this doesn't address the more systemic problem of failing to check that the values read from incoming frame data aren't from beyond the end of the pulled skb data. Build tested only. Signed-off-by: Dan Rosenberg Cc: stable@kernel.org Cc: security@kernel.org Cc: Lauro Ramos Venancio Cc: Aloisio Almeida Jr Cc: Samuel Ortiz Cc: David S. Miller Cc: Ilan Elias --- net/nfc/nci/ntf.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c index cb26461..2ab196a 100644 --- a/net/nfc/nci/ntf.c +++ b/net/nfc/nci/ntf.c @@ -106,7 +106,7 @@ static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev, nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data)); data += 2; - nfca_poll->nfcid1_len = *data++; + nfca_poll->nfcid1_len = min_t(__u8, *data++, NFC_NFCID1_MAXSIZE); pr_debug("sens_res 0x%x, nfcid1_len %d\n", nfca_poll->sens_res, nfca_poll->nfcid1_len); @@ -130,7 +130,7 @@ static __u8 *nci_extract_rf_params_nfcb_passive_poll(struct nci_dev *ndev, struct rf_tech_specific_params_nfcb_poll *nfcb_poll, __u8 *data) { - nfcb_poll->sensb_res_len = *data++; + nfcb_poll->sensb_res_len = min_t(__u8, *data++, NFC_SENSB_RES_MAXSIZE); pr_debug("sensb_res_len %d\n", nfcb_poll->sensb_res_len); @@ -145,7 +145,7 @@ static __u8 *nci_extract_rf_params_nfcf_passive_poll(struct nci_dev *ndev, __u8 *data) { nfcf_poll->bit_rate = *data++; - nfcf_poll->sensf_res_len = *data++; + nfcf_poll->sensf_res_len = min_t(__u8, *data++, NFC_SENSF_RES_MAXSIZE); pr_debug("bit_rate %d, sensf_res_len %d\n", nfcf_poll->bit_rate, nfcf_poll->sensf_res_len); @@ -331,7 +331,7 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev, switch (ntf->activation_rf_tech_and_mode) { case NCI_NFC_A_PASSIVE_POLL_MODE: nfca_poll = &ntf->activation_params.nfca_poll_iso_dep; - nfca_poll->rats_res_len = *data++; + nfca_poll->rats_res_len = min_t(__u8, *data++, 20); pr_debug("rats_res_len %d\n", nfca_poll->rats_res_len); if (nfca_poll->rats_res_len > 0) { memcpy(nfca_poll->rats_res, @@ -341,7 +341,7 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev, case NCI_NFC_B_PASSIVE_POLL_MODE: nfcb_poll = &ntf->activation_params.nfcb_poll_iso_dep; - nfcb_poll->attrib_res_len = *data++; + nfcb_poll->attrib_res_len = min_t(__u8, *data++, 50); pr_debug("attrib_res_len %d\n", nfcb_poll->attrib_res_len); if (nfcb_poll->attrib_res_len > 0) { memcpy(nfcb_poll->attrib_res, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/