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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 B005FC433E6 for ; Mon, 15 Mar 2021 11:46:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83DD064E98 for ; Mon, 15 Mar 2021 11:46:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229518AbhCOLp2 (ORCPT ); Mon, 15 Mar 2021 07:45:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229536AbhCOLpY (ORCPT ); Mon, 15 Mar 2021 07:45:24 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B0F7C061574; Mon, 15 Mar 2021 04:45:24 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id r20so15816490ljk.4; Mon, 15 Mar 2021 04:45:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=vjVaFcFS2KPU0GR3VSubynVn74gNiK4UAqEdkhZDP14=; b=m/SSTTBPYiAAUBv4tnDpAOsgVB9MAKJ0KtUuCJ33y1G0NV4YdczLMiHsDwYJ0F7Ttq hBGNJkA8oGO+WlO71tH3x2upyUBabG6oXORPmX5BW5ygwoTfX8eni+POPLsCPHWq2cio CeNbvUHhkLmfj2iKPKwdAXqhDXdAfRL/A9CPmbYprGjcUgzlSn3hfuIXjQMGCR4e0x37 Y3ieN0o22uDL2F/fpgkr8r1xdccp+nkCCQwPlCvG7NQo5WpWPRJ+pl9QEDjQ6gDWfalZ TCdw+LpvHpkIyuhpTgo1gS1IpB8BdLP7nr6V9UpN/LzrsjbO6jlkVDqaiV9nL3vjy13z r2fA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=vjVaFcFS2KPU0GR3VSubynVn74gNiK4UAqEdkhZDP14=; b=FrI09z/sQAsJRgB3yh4q91aGHHPLzgH5WqRuXWpfkOMsVkdmnxY0l1iYmKgP24qsAC jeuS3ZaW4BxQOmC9bIPc4kaS5fgMbIh16Nzws2qZarly+g6tnP0cqCRWIuawn23QOyN0 fEeOZlt7AnkVH2p0vNT6KKEwLpFxI6BcPuhp9rky5zWuZrdjMgzEyyyJtMBHdG3vbdM/ xy8G0/MW+kFp3dCLhUOucVPOLRWXm9FN6w3M5zPWIfAyZoLYVYcSLvGOToCHzIRFZepG vLPZClY6ldEZqqPKf+5xL2Ruskaey8URpYDjwE0X60fgvlAgpJcAmdtbsPYdFBuXDHwE DZkA== X-Gm-Message-State: AOAM530IhJryVWRBDotSra72mTipgStM7+k7Gkp6uoKjI6Vn+NEE94Sn NziQNmdPEcyl96w6EwrX2OI= X-Google-Smtp-Source: ABdhPJzx8iQDlbKxv1vTmHq7rJcQaw8hBkXgcXKtKQFUPZUqCq5P2Qjhu7gM3M5Ayc1XSfOljBum7g== X-Received: by 2002:a2e:95d6:: with SMTP id y22mr10256746ljh.361.1615808722604; Mon, 15 Mar 2021 04:45:22 -0700 (PDT) Received: from [192.168.1.39] (88-114-223-25.elisa-laajakaista.fi. [88.114.223.25]) by smtp.gmail.com with ESMTPSA id i16sm2851508ljj.74.2021.03.15.04.45.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 15 Mar 2021 04:45:22 -0700 (PDT) Subject: Re: [PATCH v4] mm/vmalloc: randomize vmalloc() allocations To: Uladzislau Rezki Cc: linux-hardening@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Jann Horn , Kees Cook , Linux API , Matthew Wilcox , Mike Rapoport References: <20210309135757.5406-1-toiwoton@gmail.com> <20210314172312.GA2085@pc638.lan> From: Topi Miettinen Message-ID: Date: Mon, 15 Mar 2021 13:45:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210314172312.GA2085@pc638.lan> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On 14.3.2021 19.23, Uladzislau Rezki wrote: > Also, using vmaloc test driver i can trigger a kernel BUG: > > > [ 24.627577] kernel BUG at mm/vmalloc.c:1272! It seems that most tests indeed fail. Perhaps the vmalloc subsystem isn't very robust in face of fragmented virtual memory. What could be done to fix that? In this patch, I could retry __alloc_vmap_area() with the whole region after failure of both [random, vend] and [vstart, random] but I'm not sure that would help much. Worth a try of course. By the way, some of the tests in test_vmalloc.c don't check for vmalloc() failure, for example in full_fit_alloc_test(). -Topi