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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 62656C433EF for ; Mon, 20 Sep 2021 18:56:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 410A460F93 for ; Mon, 20 Sep 2021 18:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386760AbhITS5l (ORCPT ); Mon, 20 Sep 2021 14:57:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:37162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385804AbhITSw2 (ORCPT ); Mon, 20 Sep 2021 14:52:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5DA6A615E5; Mon, 20 Sep 2021 17:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632159904; bh=eizUbIsjMYN+/U7qxJUDeZOmJ6obtyGbGnTfTb7yHFk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=akNnW5dU4Cx5qLoSXfsKOMMVVZHBfSw64ojyQUwciY/dbVxov5yQqNih9bqJdF4sa LU9LFjLIT4Q1oI+XF35+yLZ6UmeLvIzrNj4LCoWOrP6/EOgIV6QTx5JYWNDoDuEjYP P5SO7qDo/YRjufnMVhVtVYEUgSdSTIHCJYFkczGFb9EWUiTgAxlSllv50sLaS6HbXw Lf6MX2irdcNOS6dpDMa5uzOoBZVApoH5wvi68MRjYgnfbw1J2LKF/QG8yPm7ebFvWt XlY0ir1kbMIhX5qvxdMOPvg6jsZkfKYK+d7gMwixJ/l4PwQpGkCizDzOsZmVmJM9Pi vVbkpcIfjuhsg== Date: Mon, 20 Sep 2021 10:45:03 -0700 From: Mark Gross To: Arnd Bergmann Cc: Matan Ziv-Av , Hans de Goede , Mark Gross , Arnd Bergmann , "Rafael J. Wysocki" , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] platform/x86: lg-laptop: Fix possible NULL pointer derefence Message-ID: References: <20210920095556.1175269-1-arnd@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210920095556.1175269-1-arnd@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 20, 2021 at 11:55:50AM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann > > When CONFIG_DMI is disabled, dmi_get_system_info() returns a NULL > pointer, which is now caught by a warning: > > In function 'strlen', > inlined from 'acpi_add.part.0' at drivers/platform/x86/lg-laptop.c:658:6: > include/linux/fortify-string.h:25:33: error: argument 1 null where non-null expected [-Werror=nonnull] > 25 | #define __underlying_strlen __builtin_strlen > | ^ > include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen' > 60 | return __underlying_strlen(p); > | ^~~~~~~~~~~~~~~~~~~ > drivers/platform/x86/lg-laptop.c: In function 'acpi_add.part.0': > include/linux/fortify-string.h:25:33: note: in a call to built-in function '__builtin_strlen' > 25 | #define __underlying_strlen __builtin_strlen > | ^ > include/linux/fortify-string.h:60:24: note: in expansion of macro '__underlying_strlen' > 60 | return __underlying_strlen(p); > | ^~~~~~~~~~~~~~~~~~~ > > The code in there does not appear essential, so an explicit > NULL check should be sufficient. The string is also printed > to the console, but printk() is able to handle NULL pointer > arguments gracefully. > > Fixes: 8983bfd58d61 ("platform/x86: lg-laptop: Support for battery charge limit on newer models") > Signed-off-by: Arnd Bergmann > --- > drivers/platform/x86/lg-laptop.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c > index 3e520d5bca07..88b551caeaaf 100644 > --- a/drivers/platform/x86/lg-laptop.c > +++ b/drivers/platform/x86/lg-laptop.c > @@ -655,7 +655,7 @@ static int acpi_add(struct acpi_device *device) > goto out_platform_registered; > } > product = dmi_get_system_info(DMI_PRODUCT_NAME); > - if (strlen(product) > 4) > + if (product && strlen(product) > 4) seems appropriate. --mark > switch (product[4]) { > case '5': > case '6': > -- > 2.29.2 >