From patchwork Fri Dec 14 03:55:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 10730469 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-2.web.codeaurora.org (Postfix) with ESMTP id E90B513B5 for ; Fri, 14 Dec 2018 03:55:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEAC82BE50 for ; Fri, 14 Dec 2018 03:55:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C2F482C259; Fri, 14 Dec 2018 03:55:36 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,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 5A98B2C06A for ; Fri, 14 Dec 2018 03:55:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726900AbeLNDza (ORCPT ); Thu, 13 Dec 2018 22:55:30 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:33398 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726437AbeLNDza (ORCPT ); Thu, 13 Dec 2018 22:55:30 -0500 Received: by mail-pf1-f196.google.com with SMTP id c123so2166037pfb.0; Thu, 13 Dec 2018 19:55:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=33Ivcg+zKY4IJSFpoQuC8WL+BVd4+yqFaZLhoC52gcU=; b=SBJ5r/+8Ucd7I1Er4MOSSxKGDufo5jX5ud9DtvGEeeuDeN9IvB8O8DbWca9QppOKrC TwxfKWY2RjbPqRipsvKIEIJEl9vEyd0qUxVZClHBUtljQqoSoNpG4eH3gKvVuTn1hwpS 2MQa8CaWuFayaceex662ogdcUWBkO7XnFs6VBuHxJwAgZyeu5iOirf4FOPYN6UI/wIZn AKcT3McOoTh0cnUTDM4gHzx2BOPr73k23KhmtMBkWDJP7aq0y6oyXtDjc1EtjxR5aKVx PSNVLnAV+FHwLK9S9oeTSumA/xCjkMCcWJqZFOs4gOTPQyMIhx+Sx9IIY6vkc2BEsgcr c+Sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=33Ivcg+zKY4IJSFpoQuC8WL+BVd4+yqFaZLhoC52gcU=; b=er85f83he9KLwzL/HexXduLTac89LdfiKVOVD0ibtO6qs91w54srczSM8TaHlJOGK2 yU1ZGeuFe5G27YTUXFpQ9ERlFttXmiOaDMXNG4x+BCiZP7ozXUPaBmu+/IYv89ejSFKx DRdyZbiAqrCuvO7f94B72qdKCBxJIJ8PQqRT3Kkrl4D9/sCcbj330kfM66PKo6xSOmRz yh8wEzZts+UDCYOV3LgkykUeIEd2wX32FBuARGR/sKpb21v7cb0WoM9HJGU8Ng0jLWSg WaIGT0Axl2kRg/Xitha7YTyP/Go25/Xaj631Y4Ln3iEVb8qiBa/JxiFOeQ31cQzgCwm+ RreQ== X-Gm-Message-State: AA+aEWZffp4sI6V4DUlWYQEr+vpHp8c4Baa7HjaXmPIu5COHL+XhfNBq f6JoXU/V/UgWaLxwcjjLcHc= X-Google-Smtp-Source: AFSGD/V+a6oN10NcSN1A0mNAEqoLZ3rEGJxrv+M+DDU2elQcy7KmDiP8TtBcEZg61e5AwnbGcZWU+A== X-Received: by 2002:a63:bd51:: with SMTP id d17mr1342112pgp.443.1544759729682; Thu, 13 Dec 2018 19:55:29 -0800 (PST) Received: from localhost.localdomain ([2402:f000:1:4414:74ca:bc02:ba8b:bd9e]) by smtp.gmail.com with ESMTPSA id z62sm6285757pfi.4.2018.12.13.19.55.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 13 Dec 2018 19:55:28 -0800 (PST) From: Jia-Ju Bai To: pizza@shaftnet.org, kvalo@codeaurora.org, davem@davemloft.net Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan() Date: Fri, 14 Dec 2018 11:55:21 +0800 Message-Id: <20181214035521.30388-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 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 function cw1200_bss_info_changed() and cw1200_hw_scan() can be concurrently executed. The two functions both access a possible shared variable "frame.skb". This shared variable is freed by dev_kfree_skb() in cw1200_upload_beacon(), which is called by cw1200_bss_info_changed(). The free operation is protected by a mutex lock "priv->conf_mutex" in cw1200_bss_info_changed(). In cw1200_hw_scan(), this shared variable is accessed without the protection of the mutex lock "priv->conf_mutex". Thus, concurrency use-after-free bugs may occur. To fix these bugs, the original calls to mutex_lock(&priv->conf_mutex) and mutex_unlock(&priv->conf_mutex) are moved to the places, which can protect the accesses to the shared variable. Signed-off-by: Jia-Ju Bai --- drivers/net/wireless/st/cw1200/scan.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/st/cw1200/scan.c b/drivers/net/wireless/st/cw1200/scan.c index 67213f11acbd..0a9eac93dd01 100644 --- a/drivers/net/wireless/st/cw1200/scan.c +++ b/drivers/net/wireless/st/cw1200/scan.c @@ -78,6 +78,10 @@ int cw1200_hw_scan(struct ieee80211_hw *hw, if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS) return -EINVAL; + /* will be unlocked in cw1200_scan_work() */ + down(&priv->scan.lock); + mutex_lock(&priv->conf_mutex); + frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0, req->ie_len); if (!frame.skb) @@ -86,19 +90,15 @@ int cw1200_hw_scan(struct ieee80211_hw *hw, if (req->ie_len) skb_put_data(frame.skb, req->ie, req->ie_len); - /* will be unlocked in cw1200_scan_work() */ - down(&priv->scan.lock); - mutex_lock(&priv->conf_mutex); - ret = wsm_set_template_frame(priv, &frame); if (!ret) { /* Host want to be the probe responder. */ ret = wsm_set_probe_responder(priv, true); } if (ret) { + dev_kfree_skb(frame.skb); mutex_unlock(&priv->conf_mutex); up(&priv->scan.lock); - dev_kfree_skb(frame.skb); return ret; } @@ -120,10 +120,9 @@ int cw1200_hw_scan(struct ieee80211_hw *hw, ++priv->scan.n_ssids; } - mutex_unlock(&priv->conf_mutex); - if (frame.skb) dev_kfree_skb(frame.skb); + mutex_unlock(&priv->conf_mutex); queue_work(priv->workqueue, &priv->scan.work); return 0; }