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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 CD9E9C43381 for ; Tue, 2 Apr 2019 06:13:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9349A20840 for ; Tue, 2 Apr 2019 06:13:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="mPvnESYy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726858AbfDBGNz (ORCPT ); Tue, 2 Apr 2019 02:13:55 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:44718 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726337AbfDBGNz (ORCPT ); Tue, 2 Apr 2019 02:13:55 -0400 Received: by mail-pl1-f193.google.com with SMTP id g12so5703023pll.11 for ; Mon, 01 Apr 2019 23:13:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=dz17Svx6bg3Gnk30n6q9lv7bR4duyZjbUHTC6z2nKcI=; b=mPvnESYyZMOKXQVgUykQDdLbIXgpyMtlmxu6Hgt//VrRNn8L5prIus+zqjGwhemE6R 9SPV6pJKPayOkugI60m3sXjIyooC9YoiKP4AWIoqzmlGAkF8SxPjvLU3MnudMaI2pgMu VSW4wlJTvZI7BK691aL/OeK3lg5UGTuCkxaUQic98XVRKRralOJvKbnpCNruGLFSxrbO ZlF9DadweJJb+/h4FXWyT86tNc7GOAsCe1PWaGWHvXpbfwpttx0iwRk2fmU66GZwRWuL /rq25n523RbipdSNXFjs2COuXGKKU0F46dx5FPQs/jLISoO6ufpS+w55h2oSoAEe6mnV bLYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=dz17Svx6bg3Gnk30n6q9lv7bR4duyZjbUHTC6z2nKcI=; b=rfvg1Nuei6+Kn5pYNfYqT8H9wLidBF/2NQl6p9GaVg/nVrxOATlr2NfuFeE6ZzlU+Z zdT0IcZTwTHpvPVv/g5Uaiy1YIZfB5M4brdLAy4+zUdQ+SG0AGIzFEY9zg+dJbsYwLEM y+qd0Bds534xyVtsKrSXVW5DMiM5Dcx9rekDDvTPIZpHNCsN5eyTeg108IeW02H5LGxL VXWAC05UwHL1rzLceJx/XB2dtiNh0Q8ArnpCnWvUdojQ3S22DdbqahTC602hAi+lhgGF mG7yiXY7RaVw7dalreWMUBNacwwy5uHZeX7cUtiCPHXA21hK05Z17CTiKhhW0Gbw/Es6 3hCw== X-Gm-Message-State: APjAAAVmnjjPdYe950OXSthiIkVvfvu3w8y+kawgpf7Qua4hzNMS0RBW AoneOy9K8ePe6yHhRSmSwAY70A== X-Google-Smtp-Source: APXvYqzcpkihW1S1tHVqVpy/boNhCaWztaoL+PutQNTiX3b2Dmcx2aJQRdXJP2+8V3Pg8gMFIZ1n5g== X-Received: by 2002:a17:902:b94a:: with SMTP id h10mr40718646pls.82.1554185634082; Mon, 01 Apr 2019 23:13:54 -0700 (PDT) Received: from dell ([147.50.13.10]) by smtp.gmail.com with ESMTPSA id c134sm24429341pfc.87.2019.04.01.23.13.51 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 01 Apr 2019 23:13:53 -0700 (PDT) Date: Tue, 2 Apr 2019 07:13:48 +0100 From: Lee Jones To: Aditya Pakki Cc: kjlu@umn.edu, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mfd: mc13xxx: i2c/spi Fix to avoid NULL pointer dereference Message-ID: <20190402061348.GT4187@dell> References: <20190318231554.8862-1-pakki001@umn.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190318231554.8862-1-pakki001@umn.edu> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 18 Mar 2019, Aditya Pakki wrote: > of_match_device can return NULL if no matching device is found. The patches > avoids a scenario causing null pointer dereference. > > Signed-off-by: Aditya Pakki > --- > drivers/mfd/mc13xxx-i2c.c | 2 ++ > drivers/mfd/mc13xxx-spi.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/drivers/mfd/mc13xxx-i2c.c b/drivers/mfd/mc13xxx-i2c.c > index 67e4c9aa7d18..1fbc9713bb9a 100644 > --- a/drivers/mfd/mc13xxx-i2c.c > +++ b/drivers/mfd/mc13xxx-i2c.c > @@ -80,6 +80,8 @@ static int mc13xxx_i2c_probe(struct i2c_client *client, > if (client->dev.of_node) { > const struct of_device_id *of_id = > of_match_device(mc13xxx_dt_ids, &client->dev); > + if (!of_id) > + return -ENODEV; Are you sure this can happen? I don't think this is possible if client->dev.of_node is non-NULL. The 'if (client->dev.of_node)' above should see to that. > mc13xxx->variant = of_id->data; > } else { > mc13xxx->variant = (void *)id->driver_data; > diff --git a/drivers/mfd/mc13xxx-spi.c b/drivers/mfd/mc13xxx-spi.c > index ee3411cc5ce4..c044a02bdb64 100644 > --- a/drivers/mfd/mc13xxx-spi.c > +++ b/drivers/mfd/mc13xxx-spi.c > @@ -158,6 +158,8 @@ static int mc13xxx_spi_probe(struct spi_device *spi) > if (spi->dev.of_node) { > const struct of_device_id *of_id = > of_match_device(mc13xxx_dt_ids, &spi->dev); > + if (!of_id) > + return -ENODEV; > > mc13xxx->variant = of_id->data; > } else { -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog