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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 ACC00C2BA1B for ; Sun, 5 Apr 2020 17:23:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8230420675 for ; Sun, 5 Apr 2020 17:23:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="naJ+eFJh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727548AbgDERXc (ORCPT ); Sun, 5 Apr 2020 13:23:32 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:35067 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726696AbgDERXb (ORCPT ); Sun, 5 Apr 2020 13:23:31 -0400 Received: by mail-lj1-f193.google.com with SMTP id k21so12192576ljh.2 for ; Sun, 05 Apr 2020 10:23:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=yPEjuWyQ9aW5UfsWY/0pffS6lX/UZzplajlsr7ydC3s=; b=naJ+eFJhwX0b3neaEjeSBsB2hvbtuO2W56Cvko0OKp8VaOUx3T/gqXLSofntRMaMuJ X0k0OsxuPeUGM0DoqLwLLvTgs+7mSNF5fYJKWWWZEZtgjjpJxDXijV0Rvew8rawq7BDx kMDbQOMquRDvD535LSe6/pxWICoQbZPWQOa2z/d98zvon8i0JWDbGakkwP61bY/MRBQh zpgM/W7Tx/4+lfFuTxVeExRKAbjJs75is68ec4R5m41Nssh3SnSCimCRb4VEqlpTHTBx GDQrc97Axh/lNy34j/YOdsi1yU9h+7jbqqSt5ci7JzgBfTM0Zr+siA3ZYr1m58XuEqiZ UKAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=yPEjuWyQ9aW5UfsWY/0pffS6lX/UZzplajlsr7ydC3s=; b=CzjxMvuyoM4mQKycXyS7QmMtCmLa2MeFsikZJZhtCfDOumGtnC2yZbKXStQQ7b4TgM +BRH1l+Bwcnqa8rNXj7M8OySuseSmCCRg/xzpSE8iFoDjPSJN1cjWYhAVpNr3GvxKYw/ thiBaViei7onszs+7aVV7SV9kwN8R+MAiXh94/bvC5HZxkaxyTeB/Ck1l6Dj4gpwKYR/ aeWY17qXncJ1FtunKHmTGEHqWBS79qzvQp430k/B/aB7ABRatYVS38tCGQG0fDvtuuyj Lhs86x4TZNlH3u8jhVNNIjxsnGbpb7SwDCdiHvajQ4QjVJyflrtLKDRIcfuOBftnt9Wg gQig== X-Gm-Message-State: AGi0PubbY6Jm4XaTPLrNAJlPTgvUDd1PLK8WgAlmkCs7Hyo1Whk0DH+o RngNqYi+O2/sJCIjlrqcMzk= X-Google-Smtp-Source: APiQypJ3BTuzzIA14hwtV3hrEpnUo9BzlhPnRKeMd3Ofkz9hKlOrpb8TiiAzbiwNMty3Px+5pqK9jA== X-Received: by 2002:a2e:8719:: with SMTP id m25mr10222447lji.76.1586107410011; Sun, 05 Apr 2020 10:23:30 -0700 (PDT) Received: from pc636 (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id k4sm9954742lfo.47.2020.04.05.10.23.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 05 Apr 2020 10:23:29 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Sun, 5 Apr 2020 19:23:15 +0200 To: William Kucharski Cc: Uladzislau Rezki , Peter Zijlstra , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jroedel@suse.de, vbabka@suse.cz, Thomas Gleixner Subject: Re: [PATCH] mm/vmalloc: Sanitize __get_vm_area() arguments Message-ID: <20200405172315.GA8404@pc636> References: <20200404185229.GA424@pc636> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 04, 2020 at 11:25:45PM -0600, William Kucharski wrote: > > > > On Apr 4, 2020, at 12:52 PM, Uladzislau Rezki wrote: > > > >> > >> Is there any need to similarly sanitize “size” to assure start + size doesn’t go past “end?” > >> > > Why is that double check needed if all such tests are done deeper on stack? > > If such tests ARE performed, then it doesn't matter to me whether it is checked before or after, > it just seems that nothing checks whether start + size makes some sort of sense with respect > to end. > > I admit I didn't walk through all the routines to see if such a check would be superfluous. > Yes, we check it: static __always_inline bool is_within_this_va(struct vmap_area *va, unsigned long size, unsigned long align, unsigned long vstart) { ... return (nva_start_addr + size <= va->va_end); } -- Vlad Rezki