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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5345CC433E0 for ; Tue, 28 Jul 2020 15:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 245322083B for ; Tue, 28 Jul 2020 15:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595951270; bh=OupWXseUQlQcvkUuzQz9fU8bHfZdR+BlUJ5mPXy3q3c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=vSqRZdpEchJ4XVj/bHlJ6e1aWY1Ygh/7+LS5Y7LKzuXKPt0fUTf3sVBXCfNvuCNEX eCXm5E95cgz24C36rrJYk1cGzmZCOGYloA9kEkcWd3gi837gOoCpiXyT4o75XWSHpR jGu7f/DtMHUBgsbAMVOnGkMHQiieZZv2x81IIPLk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731092AbgG1Prt (ORCPT ); Tue, 28 Jul 2020 11:47:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:52052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730842AbgG1Prt (ORCPT ); Tue, 28 Jul 2020 11:47:49 -0400 Received: from kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com (unknown [163.114.132.5]) (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 778682065E; Tue, 28 Jul 2020 15:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595951268; bh=OupWXseUQlQcvkUuzQz9fU8bHfZdR+BlUJ5mPXy3q3c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sRkcOHDTdQIFMCji/m271eOdEW9f8YINHCo5V6/RmMkmocNmAbJgGsjjUibjYUaay +S8jkgUFBuNlq1xIRfDEnPwBsyrKxkJlik5oGLOgpg+nXIoz3JdrHklSA9yOKsZVbz 8rZ84FA5omZKwoYQudG+PvC0IsOKlmKDeOBKvKeE= Date: Tue, 28 Jul 2020 08:47:46 -0700 From: Jakub Kicinski To: Christoph Hellwig Cc: "David S. Miller" , Jan Engelhardt , Ido Schimmel , "Jason A. Donenfeld" , David Laight , netdev@vger.kernel.org Subject: Re: [PATCH 4/4] net: improve the user pointer check in init_user_sockptr Message-ID: <20200728084746.06f52878@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20200728063643.396100-5-hch@lst.de> References: <20200728063643.396100-1-hch@lst.de> <20200728063643.396100-5-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 28 Jul 2020 08:36:43 +0200 Christoph Hellwig wrote: > Make sure not just the pointer itself but the whole range lies in > the user address space. For that pass the length and then use > the access_ok helper to do the check. > > Fixes: 6d04fe15f78a ("net: optimize the sockptr_t for unified kernel/user address spaces") > Reported-by: David Laight > Signed-off-by: Christoph Hellwig > diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c > index 94f18d2352d007..8b132c52045973 100644 > --- a/net/ipv4/bpfilter/sockopt.c > +++ b/net/ipv4/bpfilter/sockopt.c > @@ -65,7 +65,7 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, > > if (get_user(len, optlen)) > return -EFAULT; > - err = init_user_sockptr(&optval, user_optval); > + err = init_user_sockptr(&optval, user_optval, *optlen); > if (err) > return err; > return bpfilter_mbox_request(sk, optname, optval, len, false); Appears to cause these two new warnings, sadly: net/ipv4/bpfilter/sockopt.c:68:56: warning: dereference of noderef expression net/ipv4/bpfilter/sockopt.c:68:56: warning: dereference of noderef expression