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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 975A9C433F5 for ; Mon, 30 May 2022 08:22:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233695AbiE3IW1 (ORCPT ); Mon, 30 May 2022 04:22:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233724AbiE3IWQ (ORCPT ); Mon, 30 May 2022 04:22:16 -0400 Received: from mail.meizu.com (unknown [14.29.68.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 016B21148 for ; Mon, 30 May 2022 01:22:14 -0700 (PDT) Received: from IT-EXMB-1-125.meizu.com (172.16.1.125) by mz-mail04.meizu.com (172.16.1.16) with Microsoft SMTP Server (TLS) id 14.3.487.0; Mon, 30 May 2022 16:22:15 +0800 Received: from [172.16.137.70] (172.16.137.70) by IT-EXMB-1-125.meizu.com (172.16.1.125) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Mon, 30 May 2022 16:22:12 +0800 Message-ID: <61130a41-a626-c860-e321-9295f9c9d0dd@meizu.com> Date: Mon, 30 May 2022 16:22:11 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH] staging: rtl8712: Fix pointer dereferenced before checking To: Greg Kroah-Hartman CC: Larry Finger , Florian Schilhabel , , References: <1653897933-25931-1-git-send-email-baihaowen@meizu.com> From: baihaowen In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [172.16.137.70] X-ClientProxiedBy: IT-EXMB-1-126.meizu.com (172.16.1.126) To IT-EXMB-1-125.meizu.com (172.16.1.125) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/5/30 下午4:14, Greg Kroah-Hartman 写道: > On Mon, May 30, 2022 at 04:05:32PM +0800, Haowen Bai wrote: >> The padapter->recvpriv.signal_qual_data is dereferencing before null >> checking, so move it after checking. >> >> Signed-off-by: Haowen Bai >> --- >> drivers/staging/rtl8712/rtl8712_recv.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/staging/rtl8712/rtl8712_recv.c b/drivers/staging/rtl8712/rtl8712_recv.c >> index 7f1fdd058551..8ed94b259dbe 100644 >> --- a/drivers/staging/rtl8712/rtl8712_recv.c >> +++ b/drivers/staging/rtl8712/rtl8712_recv.c >> @@ -863,10 +863,12 @@ static void process_link_qual(struct _adapter *padapter, >> { >> u32 last_evm = 0, tmpVal; >> struct rx_pkt_attrib *pattrib; >> - struct smooth_rssi_data *sqd = &padapter->recvpriv.signal_qual_data; >> + struct smooth_rssi_data *sqd; >> >> if (!prframe || !padapter) >> return; >> + >> + sqd = &padapter->recvpriv.signal_qual_data; > How can padapter ever be NULL in this codepath? > > thanks, > > greg k-h Just the original  code, show me if (!prframe || !padapter) It would be null, and then return. -- Haowen Bai