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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 E3109C282D7 for ; Sat, 2 Feb 2019 22:56:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEF0620833 for ; Sat, 2 Feb 2019 22:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727001AbfBBW4a (ORCPT ); Sat, 2 Feb 2019 17:56:30 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:46319 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726818AbfBBW4a (ORCPT ); Sat, 2 Feb 2019 17:56:30 -0500 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 1gq4D5-0007MK-Gj; Sat, 02 Feb 2019 22:56:27 +0000 From: Colin King To: Greg Kroah-Hartman , John Whitmore , devel@driverdev.osuosl.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] staging: rtl8192u: fix a null pointer dereference on a null dev pointer Date: Sat, 2 Feb 2019 22:56:27 +0000 Message-Id: <20190202225627.27116-1-colin.king@canonical.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King There is an earlier null check on pointer dev which implies it may be null, however the assignment of pointer pref and the call to free_ieee82011 on a null dev can cause null pointer dereference errors. Fix this by moving the assignment of priv and the the call to free_ieee80211 into the block of code that performs the null dev sanity check. Detected by CoverityScan, CID#143078 ("Dereference after null check") Fixes: 8fc8598e61f6 ("Staging: Added Realtek rtl8192u driver to staging") Signed-off-by: Colin Ian King --- drivers/staging/rtl8192u/r8192U_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c index 0ac0bbf7d923..4741a29326ea 100644 --- a/drivers/staging/rtl8192u/r8192U_core.c +++ b/drivers/staging/rtl8192u/r8192U_core.c @@ -4955,9 +4955,10 @@ static void rtl8192_cancel_deferred_work(struct r8192_priv *priv) static void rtl8192_usb_disconnect(struct usb_interface *intf) { struct net_device *dev = usb_get_intfdata(intf); - struct r8192_priv *priv = ieee80211_priv(dev); if (dev) { + struct r8192_priv *priv = ieee80211_priv(dev); + unregister_netdev(dev); RT_TRACE(COMP_DOWN, @@ -4969,8 +4970,8 @@ static void rtl8192_usb_disconnect(struct usb_interface *intf) priv->pFirmware = NULL; rtl8192_usb_deleteendpoints(dev); usleep_range(10000, 11000); + free_ieee80211(dev); } - free_ieee80211(dev); RT_TRACE(COMP_DOWN, "wlan driver removed\n"); } -- 2.20.1