From patchwork Thu Oct 12 09:54:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arend van Spriel X-Patchwork-Id: 10001399 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A0317602BF for ; Thu, 12 Oct 2017 09:54:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8801228BDD for ; Thu, 12 Oct 2017 09:54:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7927528C08; Thu, 12 Oct 2017 09:54:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DDCA228BDD for ; Thu, 12 Oct 2017 09:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbdJLJyV (ORCPT ); Thu, 12 Oct 2017 05:54:21 -0400 Received: from rnd-relay.smtp.broadcom.com ([192.19.229.170]:35931 "EHLO rnd-relay.smtp.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbdJLJyV (ORCPT ); Thu, 12 Oct 2017 05:54:21 -0400 Received: from mail-irv-17.broadcom.com (mail-irv-17.lvn.broadcom.net [10.75.224.233]) by rnd-relay.smtp.broadcom.com (Postfix) with ESMTP id 1061530C011; Thu, 12 Oct 2017 02:54:20 -0700 (PDT) Received: from bld-bun-01.bun.broadcom.com (bld-bun-01.bun.broadcom.com [10.176.128.83]) by mail-irv-17.broadcom.com (Postfix) with ESMTP id A4B0881EAD; Thu, 12 Oct 2017 02:54:19 -0700 (PDT) Received: by bld-bun-01.bun.broadcom.com (Postfix, from userid 25152) id 4795EB02E24; Thu, 12 Oct 2017 11:54:18 +0200 (CEST) From: Arend van Spriel To: stable@vger.kernel.org Cc: linux-wireless@vger.kernel.org, Arend van Spriel , Kevin Cernekee Subject: [PATCH] brcmfmac: add length check in brcmf_cfg80211_escan_handler() Date: Thu, 12 Oct 2017 11:54:12 +0200 Message-Id: <1507802052-14654-1-git-send-email-arend.vanspriel@broadcom.com> X-Mailer: git-send-email 1.9.1 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- Hi, Greg This backport for stable-4.4 has been compile tested on x86_64 on linux-4.4.y branch in the stable repo. Apparently I only checked that the patch applied on 4.4. Lesson learned. Thanks, Arend --- drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c index da5826d..22676a4 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c @@ -2914,6 +2914,7 @@ brcmf_cfg80211_escan_handler(struct brcmf_if *ifp, struct brcmf_cfg80211_info *cfg = ifp->drvr->config; s32 status; 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; @@ -2930,11 +2931,23 @@ brcmf_cfg80211_escan_handler(struct brcmf_if *ifp, 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); @@ -2951,9 +2964,8 @@ brcmf_cfg80211_escan_handler(struct brcmf_if *ifp, } 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; }