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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 62DF0C282C8 for ; Mon, 28 Jan 2019 17:13:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EB482082C for ; Mon, 28 Jan 2019 17:13:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548695594; bh=Ya31zp4FLM1EhnlCS2TEnTvVz+C2ZIUHpbNTsNW9rzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=E6SX9jGyovZnCa1qjbFCeHRoCLu5HO5LfGcpSKQA9IsUyNZXiZl3waRgZJHLLCHzF gluFq5su1yphH3URd9OVQxZZmFv3TCZEIUfaDrucGFo3bB6cBFnP7HHmN4PiuZ9bJ2 2bBOHVHyrYfPqiwbZA0gs2OrtarhhK0mmt0nUjOI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732137AbfA1RNL (ORCPT ); Mon, 28 Jan 2019 12:13:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:60342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730751AbfA1QI3 (ORCPT ); Mon, 28 Jan 2019 11:08:29 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0E6F82147A; Mon, 28 Jan 2019 16:08:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691708; bh=Ya31zp4FLM1EhnlCS2TEnTvVz+C2ZIUHpbNTsNW9rzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aQsJuV3GrM5eMKZvgMo0w5ekcS6n0m1z2upMoj1fzvIwYDpKmYg5gOL53UvpGU0he jvcRge1F5DSVPVL2YGegmDCdkuJh9kBxegBsIF/mL4Gts2IixgTrvSKcixsoQHXGUy oxI90bbAY6TjZK0HLkKN4CD6JZp+K61xP2MKn5fY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jia-Ju Bai , Kalle Valo , Sasha Levin , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 193/258] cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan() Date: Mon, 28 Jan 2019 10:58:19 -0500 Message-Id: <20190128155924.51521-193-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128155924.51521-1-sashal@kernel.org> References: <20190128155924.51521-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jia-Ju Bai [ Upstream commit 4f68ef64cd7feb1220232bd8f501d8aad340a099 ] 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 Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin --- 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; } -- 2.19.1