From patchwork Fri Jul 7 12:01:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Arend van Spriel X-Patchwork-Id: 9829977 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 4F256602CA for ; Fri, 7 Jul 2017 12:01:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3E7391FE95 for ; Fri, 7 Jul 2017 12:01:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 329F9281B7; Fri, 7 Jul 2017 12:01:41 +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 B80D71FE95 for ; Fri, 7 Jul 2017 12:01:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752076AbdGGMBh (ORCPT ); Fri, 7 Jul 2017 08:01:37 -0400 Received: from lpdvrndsmtp01.broadcom.com ([192.19.229.170]:51629 "EHLO rnd-relay.smtp.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892AbdGGMBh (ORCPT ); Fri, 7 Jul 2017 08:01:37 -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 CB50230C005; Fri, 7 Jul 2017 05:01:35 -0700 (PDT) Received: from jenkins-cam-14.cam.broadcom.com (jenkins-cam-14.cam.broadcom.com [10.177.128.77]) by mail-irv-17.broadcom.com (Postfix) with ESMTP id 7824A81EA4; Fri, 7 Jul 2017 05:01:35 -0700 (PDT) Received: by jenkins-cam-14.cam.broadcom.com (Postfix, from userid 25152) id B8C56B8504A; Fri, 7 Jul 2017 13:01:34 +0100 (BST) From: Arend van Spriel To: Kalle Valo Cc: Linus Torvalds , linux-wireless@vger.kernel.org, Arend van Spriel Subject: [PATCH] brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() Date: Fri, 7 Jul 2017 13:01:33 +0100 Message-Id: <1499428893-30750-1-git-send-email-arend.vanspriel@broadcom.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 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 The lower level nl80211 code in cfg80211 ensures that "len" is between 25 and NL80211_ATTR_FRAME (2304). We subtract DOT11_MGMT_HDR_LEN (24) from "len" so thats's max of 2280. However, the action_frame->data[] buffer is only BRCMF_FIL_ACTION_FRAME_SIZE (1800) bytes long so this memcpy() can overflow. memcpy(action_frame->data, &buf[DOT11_MGMT_HDR_LEN], le16_to_cpu(action_frame->len)); Reported-by: "freenerguo(郭大兴)" Signed-off-by: Arend van Spriel --- Hi Kalle, Here is the patch as Linus send it to us and security@kernel.org. I removed the lower bound check as that is already done in cfg80211. Now I signed off on the patch although formally I suppose Linus should sign it off. Putting it out there so people can respond as deemed necessary. Now fingers crossed whether patchwork will properly deal with the UTF-8 characters :-p Regards, Arend --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index cd1d673..d182a00 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -4851,6 +4851,11 @@ static int brcmf_cfg80211_stop_ap(struct wiphy *wiphy, struct net_device *ndev) cfg80211_mgmt_tx_status(wdev, *cookie, buf, len, true, GFP_KERNEL); } else if (ieee80211_is_action(mgmt->frame_control)) { + if (len > BRCMF_FIL_ACTION_FRAME_SIZE + DOT11_MGMT_HDR_LEN) { + brcmf_err("invalid action frame length\n"); + err = -EINVAL; + goto exit; + } af_params = kzalloc(sizeof(*af_params), GFP_KERNEL); if (af_params == NULL) { brcmf_err("unable to allocate frame\n");