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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 4270BC4360C for ; Sun, 6 Oct 2019 18:11:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C1522053B for ; Sun, 6 Oct 2019 18:11:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=googlemail.com header.i=@googlemail.com header.b="JqZwTLTB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727108AbfJFSL1 (ORCPT ); Sun, 6 Oct 2019 14:11:27 -0400 Received: from mail-vk1-f194.google.com ([209.85.221.194]:38414 "EHLO mail-vk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726559AbfJFSL0 (ORCPT ); Sun, 6 Oct 2019 14:11:26 -0400 Received: by mail-vk1-f194.google.com with SMTP id s72so2496911vkh.5; Sun, 06 Oct 2019 11:11:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=XvhZjKNZd7ezMcvYLdUk4d1cF2+Jz0JmAVSLszIBT2A=; b=JqZwTLTBp0H21eSD9zA8Q1JSuXLhZKi7280qCXLWNDa1vX10J2yxVcXrL16QdtUBHc pScVR9B4JReFA2lfJRixZS3CbtSxM72X2/JB5xyQGWhFZ7aW9lYzMHKADT0TAwuUYT6y fd0q+u8xzBDFujeR4IZaTIiLWU8G6xSR1lQJI0DGMSSB8RAQC1C/CDsiE9ESKClMtWrT SAnqYhCjzB6I7qKJxmJgagNFt6CU5AymX6FLNLJ5NqhdSoUxcm1CYOzOJO48EfJO5dX4 cuhKe2+IlBv/71jVH8LP9xRkhJl7stAqVp1WhHxKlKHi1UvXoFWdmldAdOxPPpYZ92VE AYmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XvhZjKNZd7ezMcvYLdUk4d1cF2+Jz0JmAVSLszIBT2A=; b=BcfTHUMsVu+cBYySQ9INou3NNOLk7vl/7K58R0mzLXoMmHYv5gGvpp+2Mq6MicaroE PFJt6GgIyEbUY5FK7QYNEx+DcsU1ZfXzxWc5F6QqjqzVsfxLh32JA7sDGTaWufAQ24Vj 94NAw2NBes8OUg2OivANhK007TTaix/BxS+1ackx2l//0W1BDC0hFytDCf17M12G+349 MKouz2zQamv95SY50abpxeZfXI2LIABqe3zHiLVBQsMn8W5VpWbES2o2v8JXxDbqoX5j ZR0soUSRcHKD67/ujq1VLf20TLT3r+t8PQIaMVBcq628bvD0HgmK3hpbSgpd5BN/DmyX KrEA== X-Gm-Message-State: APjAAAVnOZBVNi3tMRcOCLClCqC7aTGqLt7U1niFyrzOUEEfY36t1/l6 7hTwa5Yn2WR66sJVJ7AJLibElm/zvT5NtL3XzUU= X-Google-Smtp-Source: APXvYqxuW3H8XQIumbD21ksD8zppbT4zFvS2Lqcjei2gxAhaMSAXkJ/r6UQnGb4Eyn+eJNoiJigfqPfjsFvR+e1x15o= X-Received: by 2002:a1f:a705:: with SMTP id q5mr12627945vke.85.1570385484250; Sun, 06 Oct 2019 11:11:24 -0700 (PDT) MIME-Version: 1.0 References: <20191006163314.23191-1-aford173@gmail.com> In-Reply-To: <20191006163314.23191-1-aford173@gmail.com> From: Yegor Yefremov Date: Sun, 6 Oct 2019 20:11:14 +0200 Message-ID: Subject: Re: [PATCH V2 1/2] serial: mctrl_gpio: Check for NULL pointer To: Adam Ford Cc: linux-serial@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , Andy Shevchenko , Vignesh R , Mika Westerberg , Douglas Anderson , Tony Lindgren , kernel list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 6, 2019 at 6:33 PM Adam Ford wrote: > > When using mctrl_gpio_to_gpiod, it dereferences gpios into a single > requested GPIO. This dereferencing can break if gpios is NULL, > so this patch adds a NULL check before dereferencing it. If > gpios is NULL, this function will also return NULL. > > Signed-off-by: Adam Ford Reviewed-by: Yegor Yefremov > --- > V2: This patch is new to the V2 of this series, so patch 2/2 can > work without risking a NULL dereference > diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c > index d9074303c88e..fb4781292d40 100644 > --- a/drivers/tty/serial/serial_mctrl_gpio.c > +++ b/drivers/tty/serial/serial_mctrl_gpio.c > @@ -66,6 +66,9 @@ EXPORT_SYMBOL_GPL(mctrl_gpio_set); > struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, > enum mctrl_gpio_idx gidx) > { > + if (gpios == NULL) > + return NULL; > + > return gpios->gpio[gidx]; > } > EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod); > -- > 2.17.1 >