From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932900AbdKFX7Q (ORCPT ); Mon, 6 Nov 2017 18:59:16 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52737 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932824AbdKFXyk (ORCPT ); Mon, 6 Nov 2017 18:54:40 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Arend Van Spriel" , "Kevin Cernekee" , "Pieter-Paul Giesberts" , "Franky Lin" , "Hante Meuleman" , "Kalle Valo" Date: Mon, 06 Nov 2017 23:03:02 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 183/294] brcmfmac: add length check in brcmf_cfg80211_escan_handler() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.50-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arend Van Spriel commit 17df6453d4be17910456e99c5a85025aa1b7a246 upstream. Upon handling the firmware notification for scans the length was checked properly and may result in corrupting kernel heap memory due to buffer overruns. This fix addresses CVE-2017-0786. Cc: Kevin Cernekee Reviewed-by: Hante Meuleman Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Franky Lin Signed-off-by: Arend van Spriel Signed-off-by: Kalle Valo [bwh: Backported to 3.16: - Use WL_ESCAN_BUF_SIZE instead of BRCMF_ESCAN_BUF_SIZE - Adjust filename] Signed-off-by: Ben Hutchings --- .../wireless/brcm80211/brcmfmac/wl_cfg80211.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) --- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c @@ -2692,6 +2692,7 @@ brcmf_cfg80211_escan_handler(struct brcm s32 status; s32 err = 0; struct brcmf_escan_result_le *escan_result_le; + u32 escan_buflen; struct brcmf_bss_info_le *bss_info_le; struct brcmf_bss_info_le *bss = NULL; u32 bi_length; @@ -2708,11 +2709,23 @@ brcmf_cfg80211_escan_handler(struct brcm if (status == BRCMF_E_STATUS_PARTIAL) { brcmf_dbg(SCAN, "ESCAN Partial result\n"); + if (e->datalen < sizeof(*escan_result_le)) { + brcmf_err("invalid event data length\n"); + goto exit; + } escan_result_le = (struct brcmf_escan_result_le *) data; if (!escan_result_le) { brcmf_err("Invalid escan result (NULL pointer)\n"); goto exit; } + escan_buflen = le32_to_cpu(escan_result_le->buflen); + if (escan_buflen > WL_ESCAN_BUF_SIZE || + escan_buflen > e->datalen || + escan_buflen < sizeof(*escan_result_le)) { + brcmf_err("Invalid escan buffer length: %d\n", + escan_buflen); + goto exit; + } if (le16_to_cpu(escan_result_le->bss_count) != 1) { brcmf_err("Invalid bss_count %d: ignoring\n", escan_result_le->bss_count); @@ -2729,9 +2742,8 @@ brcmf_cfg80211_escan_handler(struct brcm } bi_length = le32_to_cpu(bss_info_le->length); - if (bi_length != (le32_to_cpu(escan_result_le->buflen) - - WL_ESCAN_RESULTS_FIXED_SIZE)) { - brcmf_err("Invalid bss_info length %d: ignoring\n", + if (bi_length != escan_buflen - WL_ESCAN_RESULTS_FIXED_SIZE) { + brcmf_err("Ignoring invalid bss_info length: %d\n", bi_length); goto exit; }