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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 AAF89C4360F for ; Tue, 26 Mar 2019 19:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8572F20823 for ; Tue, 26 Mar 2019 19:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732505AbfCZTuy (ORCPT ); Tue, 26 Mar 2019 15:50:54 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:49750 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732176AbfCZTux (ORCPT ); Tue, 26 Mar 2019 15:50:53 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id EBF3014C66CFA; Tue, 26 Mar 2019 12:50:51 -0700 (PDT) Date: Tue, 26 Mar 2019 12:50:51 -0700 (PDT) Message-Id: <20190326.125051.1865224055641059773.davem@davemloft.net> To: mojha@codeaurora.org Cc: kjlu@umn.edu, alexandre.torgue@st.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, joabreu@synopsys.com, mcoquelin.stm32@gmail.com, pakki001@umn.edu, peppe.cavallaro@st.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] net: stmmac: fix a potential NULL pointer dereference From: David Miller In-Reply-To: <0f518f7a-ff1f-b8d9-8468-a1f7648ada46@codeaurora.org> References: <20190323033942.21796-1-kjlu@umn.edu> <0f518f7a-ff1f-b8d9-8468-a1f7648ada46@codeaurora.org> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 26 Mar 2019 12:50:52 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mukesh Ojha Date: Tue, 26 Mar 2019 15:27:03 +0530 > > On 3/23/2019 9:09 AM, Kangjie Lu wrote: >> In case of_device_get_match_data fails, the fix return -EINVAL >> to avoid the NULL pointer dereference. >> >> Signed-off-by: Kangjie Lu >> --- >> drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> index 3256e5cbad27..344ead5949b1 100644 >> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> @@ -485,6 +485,8 @@ static int dwc_eth_dwmac_remove(struct >> platform_device *pdev) >> int err; >> data = of_device_get_match_data(&pdev->dev); >> + if (!data) >> + return -EINVAL; > > Although, it is false alarm for this driver as of_match_table is not > NULL, but it would be good to add the check. I disagree. This is adding a check just for the sake of adding the check and shutting up a static analysis tool. Now, if the tool looked at the table entries being fed into this function, and found such a posibility then we would fix the bug and still not add the check. 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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 90E71C43381 for ; Tue, 26 Mar 2019 19:51:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 624BF20823 for ; Tue, 26 Mar 2019 19:51:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="gs10XVfU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 624BF20823 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: From:Subject:To:Message-Id:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EsJpg374JJBqrkYY7Fyr/ydddPtexPR34+9or18rQAU=; b=gs10XVfUc0N2Ek KPtyqEqKefTeZqeLRYYGUodleiEajySU1Kdn3ry96qUf3gC5QUtH3C6i1ZbNxabDm27L3Qxie9YHr bUU2seBhZtRiOQ3p/GkHp9fj0VYEep0DJDb0BSWp0MCd6JV73k+U2Be0JvrIkumGICU+U9MYnOwIW jB+ANhK3pvaPEO+uqvZUK3o/VbWfy4DSB+AmI8cdm7f7fa+ZCgFytiLrinBqazSTqEiypgLoFCEF+ dz0gm1KqovEJsGcPNIJ+UcxtdMPuS5tvVGe0cgjyCmtx8tL1hsQ1CyOFEe3uD3yg6c2BMubSZ07QD ummrPnaQuR85quu3oJeA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h8s6C-0005Lx-90; Tue, 26 Mar 2019 19:51:04 +0000 Received: from shards.monkeyblade.net ([2620:137:e000::1:9]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h8s66-0005LC-S6 for linux-arm-kernel@lists.infradead.org; Tue, 26 Mar 2019 19:51:02 +0000 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id EBF3014C66CFA; Tue, 26 Mar 2019 12:50:51 -0700 (PDT) Date: Tue, 26 Mar 2019 12:50:51 -0700 (PDT) Message-Id: <20190326.125051.1865224055641059773.davem@davemloft.net> To: mojha@codeaurora.org Subject: Re: [PATCH] net: stmmac: fix a potential NULL pointer dereference From: David Miller In-Reply-To: <0f518f7a-ff1f-b8d9-8468-a1f7648ada46@codeaurora.org> References: <20190323033942.21796-1-kjlu@umn.edu> <0f518f7a-ff1f-b8d9-8468-a1f7648ada46@codeaurora.org> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 26 Mar 2019 12:50:52 -0700 (PDT) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190326_125058_942382_56B61031 X-CRM114-Status: GOOD ( 12.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alexandre.torgue@st.com, netdev@vger.kernel.org, kjlu@umn.edu, linux-kernel@vger.kernel.org, joabreu@synopsys.com, mcoquelin.stm32@gmail.com, pakki001@umn.edu, peppe.cavallaro@st.com, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Mukesh Ojha Date: Tue, 26 Mar 2019 15:27:03 +0530 > > On 3/23/2019 9:09 AM, Kangjie Lu wrote: >> In case of_device_get_match_data fails, the fix return -EINVAL >> to avoid the NULL pointer dereference. >> >> Signed-off-by: Kangjie Lu >> --- >> drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> index 3256e5cbad27..344ead5949b1 100644 >> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c >> @@ -485,6 +485,8 @@ static int dwc_eth_dwmac_remove(struct >> platform_device *pdev) >> int err; >> data = of_device_get_match_data(&pdev->dev); >> + if (!data) >> + return -EINVAL; > > Although, it is false alarm for this driver as of_match_table is not > NULL, but it would be good to add the check. I disagree. This is adding a check just for the sake of adding the check and shutting up a static analysis tool. Now, if the tool looked at the table entries being fed into this function, and found such a posibility then we would fix the bug and still not add the check. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel