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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CD7F5C47404 for ; Fri, 11 Oct 2019 13:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3908214AF for ; Fri, 11 Oct 2019 13:51:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=bfs.de header.i=@bfs.de header.b="i4tiEkK/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728158AbfJKNve (ORCPT ); Fri, 11 Oct 2019 09:51:34 -0400 Received: from mx01-fr.bfs.de ([193.174.231.67]:18002 "EHLO mx01-fr.bfs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728027AbfJKNvd (ORCPT ); Fri, 11 Oct 2019 09:51:33 -0400 Received: from mail-fr.bfs.de (mail-fr.bfs.de [10.177.18.200]) by mx01-fr.bfs.de (Postfix) with ESMTPS id 38B8120345; Fri, 11 Oct 2019 15:51:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bfs.de; s=dkim201901; t=1570801887; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dBPwyrLZ6ynWgdIN1/EoRSAZNcdAcNFjCEE4a11LTSk=; b=i4tiEkK/QbVddoZFA3tXOP7m+D+6aMgKz8kUZAYgBnnOWKjXZrwOJfldAGoybCKm9lKbgf uk+U7MEPhPL5NDxL/qI8EaZX0Ji5dVnwqPLBPEl5oZ3SmClICnxRi7rBg/18WFbaN/SqIU eGKDov3DoPujBJk3m9yFtFrMm6V+/Z3NY/fYMVlf9yC80m2mEF1T/CLDJuIvAZVxqb2pHd +PffSeQXvrRE43m38hyCzW64FPfUI3J62up/40XyLcFXtAw01ZnxT/pwV5AZjjh0e3tVZR oUgy5XX9HXy1qjWSqmpheEz1fI31GANpU+soI4TBIv0WJq2VjWxwl+HwO9fJPw== Received: from [134.92.181.33] (unknown [134.92.181.33]) by mail-fr.bfs.de (Postfix) with ESMTPS id E8F6ABEEBD; Fri, 11 Oct 2019 15:51:26 +0200 (CEST) Message-ID: <5DA088DE.5040902@bfs.de> Date: Fri, 11 Oct 2019 15:51:26 +0200 From: walter harms Reply-To: wharms@bfs.de User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Dan Carpenter CC: Juergen Stuber , Johan Hovold , Greg Kroah-Hartman , legousb-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] USB: legousbtower: fix a signedness bug in tower_probe() References: <20191011133525.GB22905@mwanda> In-Reply-To: <20191011133525.GB22905@mwanda> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Authentication-Results: mx01-fr.bfs.de X-Spamd-Result: default: False [-3.10 / 7.00]; ARC_NA(0.00)[]; HAS_REPLYTO(0.00)[wharms@bfs.de]; BAYES_HAM(-3.00)[100.00%]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; REPLYTO_ADDR_EQ_FROM(0.00)[]; DKIM_SIGNED(0.00)[]; RCPT_COUNT_SEVEN(0.00)[7]; NEURAL_HAM(-0.00)[-0.999,0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[] Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Am 11.10.2019 15:35, schrieb Dan Carpenter: > The problem is that sizeof() is unsigned long so negative error codes > are type promoted to high positive values and the condition becomes > false. > > Fixes: 1d427be4a39d ("USB: legousbtower: fix slab info leak at probe") > Signed-off-by: Dan Carpenter > --- > drivers/usb/misc/legousbtower.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c > index 9d4c52a7ebe0..835908fe1e65 100644 > --- a/drivers/usb/misc/legousbtower.c > +++ b/drivers/usb/misc/legousbtower.c > @@ -881,7 +881,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device > get_version_reply, > sizeof(*get_version_reply), > 1000); > - if (result < sizeof(*get_version_reply)) { > + if (result < 0 || result < sizeof(*get_version_reply)) { > if (result >= 0) > result = -EIO; > dev_err(idev, "get version request failed: %d\n", result); i am not an USB expert but it seems that this is a complicated way to check for result != sizeof(*get_version_reply). re, wh