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 E6E72C27C76 for ; Sat, 28 Jan 2023 17:28:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234524AbjA1R2k (ORCPT ); Sat, 28 Jan 2023 12:28:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234073AbjA1R2i (ORCPT ); Sat, 28 Jan 2023 12:28:38 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B1E6233ED; Sat, 28 Jan 2023 09:28:37 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BB63EB806A0; Sat, 28 Jan 2023 17:28:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22D90C433EF; Sat, 28 Jan 2023 17:28:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674926914; bh=eavz0MMuJlAPnvVE2PM75ag4JmsVT4sDhzf+WOsIp5A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rVUEWtnJMQHVpfW8Ei9Fh2DQaEiQAZuhqrqvsQWUaFf7LdHSueNoiEOsvRSM3k0yC tDLyoMC/1U7Ty92YgazIIP6wgpMwd2ZUyBoE+3uzl3/KpJe2f+rUjGUejO5H4obGif lP9emKC++TH/dZ8lzOTb3aZTB4eJW7yowot1GdqU2CZUYKRreARkyDMNOqzJsMfX5F wjPQapNH4DqjtavHVXDk1qg/g0uLB5gVnpWi+2s1kmwQE7h1Pd/R+44RIvZLiXGatP dLs17QN9ZhhGW8qTh2xRI2y1DkJqtfn5IG2Fh+amzvboHUlz4r86ZrYTflO2+Lvl8L 8rUSDi+UPrBxQ== Date: Sat, 28 Jan 2023 17:42:27 +0000 From: Jonathan Cameron To: Harshit Mogalapalli Cc: error27@gmail.com, Lars-Peter Clausen , Irina Tirdea , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iio: accel: mma9551_core: Prevent uninitialized variable in mma9551_read_config_word() Message-ID: <20230128174227.7c240576@jic23-huawei> In-Reply-To: <20230126153610.3586243-1-harshit.m.mogalapalli@oracle.com> References: <20230126153610.3586243-1-harshit.m.mogalapalli@oracle.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.36; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 26 Jan 2023 07:36:09 -0800 Harshit Mogalapalli wrote: > Smatch Warns: > drivers/iio/accel/mma9551_core.c:299 > mma9551_read_config_word() error: uninitialized symbol 'v'. > > When (offset >= 1 << 12) is true mma9551_transfer() will return -EINVAL > without 'v' being initialized, so check for the error and return. > > Fixes: 40cb761306d6 ("iio: add driver for Freescale MMA9553") > Signed-off-by: Harshit Mogalapalli Similar to previous. It's tidying up an inelegant bit of code, but no actual bug due to checks at the caller. Hence I've dropped the fixes tag and added a note to the commit description for anyone considering backporting. Applied to the togreg branch of iio.git and pushed out as testing for 0-day to take a look at it and see if we missed anything. Thanks, Jonathan > --- > This is detected using static analysis. > --- > drivers/iio/accel/mma9551_core.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/accel/mma9551_core.c b/drivers/iio/accel/mma9551_core.c > index 64ca7d7a9673..75eee7f7303a 100644 > --- a/drivers/iio/accel/mma9551_core.c > +++ b/drivers/iio/accel/mma9551_core.c > @@ -296,9 +296,12 @@ int mma9551_read_config_word(struct i2c_client *client, u8 app_id, > > ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG, > reg, NULL, 0, (u8 *)&v, 2); > + if (ret < 0) > + return ret; > + > *val = be16_to_cpu(v); > > - return ret; > + return 0; > } > EXPORT_SYMBOL_NS(mma9551_read_config_word, IIO_MMA9551); >