From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E948DC00140 for ; Mon, 8 Aug 2022 08:42:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236257AbiHHImr (ORCPT ); Mon, 8 Aug 2022 04:42:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236156AbiHHImo (ORCPT ); Mon, 8 Aug 2022 04:42:44 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D66D462DB for ; Mon, 8 Aug 2022 01:42:43 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id q7-20020a17090a7a8700b001f300db8677so8392396pjf.5 for ; Mon, 08 Aug 2022 01:42:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=/V5YRzrrngmrKnPlwjf2mgGczmcX1pFkUBvlD3ol0Bc=; b=GQnd9TY1YEzi5kl2Lpj5+BraYFv5K2KMYpqyeBGSJX6Ps2WZx6/vOZrvXXT6BdDe9N rPt38lus/dthOJHWQ/BqlCgrV9PUQAFLO0bjVkVy49GYKCeIg/ghmEoM7hG22+ZfvANO WwHAk1xRJtmZ+unsjz/xoUL1MbP1E10HzG/GWA/wno3uGH1NEDCQQwRxMSNJH+EgSgmY zFHHddStYltjqR+0+DbBy+SPTxX8WuILn6nyRLe2iwjiDwFoTk7tduaNHbnts9iKwAZ0 emjGWfKkTHTGiJZBfHzBxOHiqtu/3BuVbk3xnA6OtC/lHnYDTtKDDRN4sH6QRVwyFwO8 l5Sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=/V5YRzrrngmrKnPlwjf2mgGczmcX1pFkUBvlD3ol0Bc=; b=CMPBe7OLCGMAl5xH96rseLZqdJldjrjKIanJqx1ep+jg0B+q2KEveI8DxR152fxXup eZtF0TDVVxAkwDUu0zJmxKpRL7Gv4hL9x3hfQO+Rvg05fdpRDFvCj0nOjTdLqnH+O6T+ gubnl99eJntnu0O2WEwTH+hZRkGvwDIFlon3O3KOvBQvI+Agwl8hFL4mLC21m+eM7dDt MLV3DkxoguYCuuPyd7JC1OZUFOLvrMr1WeOmTB2FdsLB30P/DtRz/k5X1cw5H/ADZflI wUqJOaPwLkBtTIGjHwft5rPym2a8ZUJcqAxDwJwg8POC8k8gljldod8p6OcY634gGj9U e2qA== X-Gm-Message-State: ACgBeo3DRqCiEXZprXUSGo/zE6qhZLgQm8vzteZUtwH6udc1w5bUIeQJ vN0U2yRTr63lttDc+AB4b2M= X-Google-Smtp-Source: AA6agR44OLGo625i4Bej3GHWTf+RtfAVSgb5b0BWvS61bFpz6lApAKhjRNmeHHHnrCpuRus185/zPw== X-Received: by 2002:a17:902:ecce:b0:16e:e6e9:69b9 with SMTP id a14-20020a170902ecce00b0016ee6e969b9mr17667827plh.139.1659948163208; Mon, 08 Aug 2022 01:42:43 -0700 (PDT) Received: from [10.176.68.61] ([192.19.148.250]) by smtp.gmail.com with ESMTPSA id b4-20020a170902d40400b0016f1319d2aasm7984242ple.171.2022.08.08.01.42.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Aug 2022 01:42:42 -0700 (PDT) Message-ID: Date: Mon, 8 Aug 2022 10:42:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.12.0 Subject: Re: [PATCH] brcmfmac: fix use-after-free bug Content-Language: en-US To: Alexander Coffin , Franky Lin , Hante Meuleman Cc: linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, SHA-cyfmac-dev-list@infineon.com References: <20220802172823.1696680-1-alex.coffin@matician.com> <20220802172823.1696680-2-alex.coffin@matician.com> From: Arend Van Spriel In-Reply-To: <20220802172823.1696680-2-alex.coffin@matician.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 8/2/2022 7:28 PM, Alexander Coffin wrote: > A commit message would have been nice... > Signed-off-by: Alexander Coffin > --- > drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c > index 87aef211b35f..12ee8b7163fd 100644 > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c > @@ -296,6 +296,7 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb, > struct brcmf_pub *drvr = ifp->drvr; > struct ethhdr *eh; > int head_delta; > + unsigned int tx_bytes = skb->len; > > brcmf_dbg(DATA, "Enter, bsscfgidx=%d\n", ifp->bsscfgidx); > > @@ -370,7 +371,7 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb, > ndev->stats.tx_dropped++; > } else { > ndev->stats.tx_packets++; > - ndev->stats.tx_bytes += skb->len; > + ndev->stats.tx_bytes += tx_bytes; Why would this be a use-after-free? We only get here when ret is zero. In that case the skb is not freed. If there would be a commit message with some error report that proofs there is a use-after-free I would look into this further, but now I just say NAK. Regards, Arend > } > > /* Return ok: we always eat the packet */