From patchwork Fri Jun 30 10:08:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 9819083 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 1934560224 for ; Fri, 30 Jun 2017 10:12:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0B4E0285C2 for ; Fri, 30 Jun 2017 10:12:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F3942285EA; Fri, 30 Jun 2017 10:12:51 +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=unavailable 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 959CE285C2 for ; Fri, 30 Jun 2017 10:12:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752685AbdF3KIy (ORCPT ); Fri, 30 Jun 2017 06:08:54 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59028 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752653AbdF3KIt (ORCPT ); Fri, 30 Jun 2017 06:08:49 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1dQsqy-0004Wg-9i; Fri, 30 Jun 2017 10:08:44 +0000 From: Colin King To: Larry Finger , Chaoming Li , Kalle Valo , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][-next] rtlwifi: kfree entry until after entry->bssid has been accessed Date: Fri, 30 Jun 2017 11:08:43 +0100 Message-Id: <20170630100843.9188-1-colin.king@canonical.com> X-Mailer: git-send-email 2.11.0 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 From: Colin Ian King The current code kfree's entry and then dereferences it by accessing entry->bssid. Avoid the dereference-after-free by moving the kfree after the access to entry->bssid. Detected by CoverityScan, CID#1448600 ("Read from pointer after free") Signed-off-by: Colin Ian King --- drivers/net/wireless/realtek/rtlwifi/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/base.c b/drivers/net/wireless/realtek/rtlwifi/base.c index e36ee592c660..208f56297a75 100644 --- a/drivers/net/wireless/realtek/rtlwifi/base.c +++ b/drivers/net/wireless/realtek/rtlwifi/base.c @@ -1735,12 +1735,12 @@ void rtl_scan_list_expire(struct ieee80211_hw *hw) continue; list_del(&entry->list); - kfree(entry); rtlpriv->scan_list.num--; RT_TRACE(rtlpriv, COMP_SCAN, DBG_LOUD, "BSSID=%pM is expire in scan list (total=%d)\n", entry->bssid, rtlpriv->scan_list.num); + kfree(entry); } spin_unlock_irqrestore(&rtlpriv->locks.scan_list_lock, flags);