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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09035C43219 for ; Fri, 3 May 2019 13:09:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC8982070B for ; Fri, 3 May 2019 13:09:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="ayqNl+TM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727897AbfECNJi (ORCPT ); Fri, 3 May 2019 09:09:38 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:46172 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726377AbfECNJi (ORCPT ); Fri, 3 May 2019 09:09:38 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x43CxSMG125045; Fri, 3 May 2019 13:09:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2018-07-02; bh=qUI30iuQjAmm87uWs76TDx2QVxkW3XKVNbir16Y2Z1Y=; b=ayqNl+TM2CCC+3wJRrsmGVGPU9GDWP8839ASLcJMQflgrcapOpISKzsYecxW7MFAGrB3 /fPSDCMjnLr4PWTz0jR1kmmrwKkqA44B+m43wh+7tdJYieomyq6jpR8WReR8e9hSOCaI ueQ/pnwaCQSXSXxc3RlKtJXGguWH9DBCEwSs+fRkjQjL+SJ/mkyp8FxQ+3eNlS8DEKY/ Lx4sOaGz3k6s7Q0XIzyScCVyoAonLK0Oci0ZrHQJKKWdLOWGZxDOBvxPKD+dU+6uQSmn DubFPCWUsNPwJGN8Sa1hP8OmHutsSfJ5Xh+6ZUCFToSjaFoCpN7lnvYZk7qc8/1EE+mR 5w== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 2s6xhypkrf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 03 May 2019 13:09:24 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x43D99DA136935; Fri, 3 May 2019 13:09:24 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2s6xhhm5p0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 03 May 2019 13:09:24 +0000 Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x43D9LGj029163; Fri, 3 May 2019 13:09:22 GMT Received: from mwanda (/196.104.111.181) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 03 May 2019 06:09:21 -0700 Date: Fri, 3 May 2019 16:09:13 +0300 From: Dan Carpenter To: Felix Fietkau , Ryder Lee Cc: Lorenzo Bianconi , Roy Luo , Kalle Valo , Matthias Brugger , linux-wireless@vger.kernel.org, linux-mediatek@lists.infradead.org, kernel-janitors@vger.kernel.org Subject: [PATCH] mt76: mt7615: Use after free in mt7615_mcu_set_bcn() Message-ID: <20190503130909.GI29695@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email haha only kidding User-Agent: Mutt/1.10.1 (2018-07-13) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9245 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=837 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905030082 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9245 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=865 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905030082 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org We dereference "skb" when we assign: req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); ^^^^^^^^ So this patch just moves the dev_kfree_skb() down a bit to avoid the use after free. Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chipsets") Signed-off-by: Dan Carpenter --- drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c index ea67c6022fe6..dc1301effa24 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL, 0, NULL); memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len); - dev_kfree_skb(skb); req.omac_idx = mvif->omac_idx; req.enable = en; @@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); req.tim_ie_pos = cpu_to_le16(MT_TXD_SIZE + tim_off); + dev_kfree_skb(skb); skb = mt7615_mcu_msg_alloc(&req, sizeof(req)); return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD, -- 2.18.0