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=-10.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 A03ACC433DF for ; Wed, 26 Aug 2020 14:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C2EC214F1 for ; Wed, 26 Aug 2020 14:39:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598452793; bh=MPfx5aMRKvl6ZwBRmQ7wZoUEayNIgC3zvUTNwgksdSU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=r5IXgvDryMKDfYjrKUcIkiUu945OE2ZW3/5l72M3uNhurT0biPYIILEE1Q4fPqVWY rpqtvuFrsm0HIm4KNLsEE1TC4zVGxpAlxGlcD5ryckHapMKHMrriiZTEYlVtEGNPIU xE6p7f64RcfCdv7X7uUSDISoTMC68D0OMnJhjRbI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726788AbgHZOjv (ORCPT ); Wed, 26 Aug 2020 10:39:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:49888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbgHZOjv (ORCPT ); Wed, 26 Aug 2020 10:39:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6614A2177B; Wed, 26 Aug 2020 14:39:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598452790; bh=MPfx5aMRKvl6ZwBRmQ7wZoUEayNIgC3zvUTNwgksdSU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KiYrI2soBiXl7DPVV0RzATq2/1Ocm5qQ6CI5eH7flFsCHyC+pNxXpDA/ZoRk10tFT pp18pv46oDlUwUlOjMRphDG2sA2C7jBTigsPDVHy/urYkMKQ3I9t6LDwD/Ln4pDUMk z9JV2hcMyjmNq/Gq+1Ry83IdXuMcbDZzhXZXKOSc= Date: Wed, 26 Aug 2020 16:40:06 +0200 From: Greg KH To: trix@redhat.com Cc: arnd@arndb.de, rikard.falkeborn@gmail.com, rogerable@realtek.com, lee.jones@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] misc: rtsx: improve status check Message-ID: <20200826144006.GA4178874@kroah.com> References: <20200826135337.17105-1-trix@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200826135337.17105-1-trix@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 26, 2020 at 06:53:37AM -0700, trix@redhat.com wrote: > From: Tom Rix > > clang static analysis flags this error > > rtsx_usb.c:505:10: warning: The left operand of '&' > is a garbage value > if (val & cd_mask[card]) > ~~~ ^ > > val is set when rtsx_usb_get_card_status() is successful. The > problem is how it checks its callers returns. > > /* usb_control_msg may return positive when success */ > if (ret < 0) > return ret; > > This is correct for the usb_control_msg() the call. However, > the call to rtsx_usb_get_status_with_bulk is only successful > when 0 is returned. > > So make status checking block specific. > > Fixes: 730876be2566 ("mfd: Add realtek USB card reader driver") > Signed-off-by: Tom Rix > --- > drivers/misc/cardreader/rtsx_usb.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c > index 59eda55d92a3..bd392b0c66af 100644 > --- a/drivers/misc/cardreader/rtsx_usb.c > +++ b/drivers/misc/cardreader/rtsx_usb.c > @@ -304,14 +304,15 @@ int rtsx_usb_get_card_status(struct rtsx_ucr *ucr, u16 *status) > *status = *buf; > > kfree(buf); > + > + /* usb_control_msg may return positive when success */ it _WILL_ return positive. it will return negative for an error. It will never return 0. > + if (ret < 0) > + return ret; > } else { > ret = rtsx_usb_get_status_with_bulk(ucr, status); > + if (ret) > + return ret; > } > - > - /* usb_control_msg may return positive when success */ > - if (ret < 0) > - return ret; > - I fail to see how this code is incorrect today. Well, I do see a bug in here, but you aren't fixing it (short read is not checked), see the recent linux-usb@vger mail thread about that problem that we will be fixing tree-wide over time soon... How can your move of these lines modify anything? thanks, greg k-h