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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C04DCC38A2D for ; Mon, 24 Oct 2022 23:42:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230294AbiJXXmC (ORCPT ); Mon, 24 Oct 2022 19:42:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230213AbiJXXlf (ORCPT ); Mon, 24 Oct 2022 19:41:35 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53EE5B1B9F for ; Mon, 24 Oct 2022 15:00:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666648809; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=aS4yi1vMu6K7Mzb0dwDEe+zwP7hRRYhJ4HxVAVJl5ro=; b=A0h3L+3OFO2hZeJ50KNvTH8BKCDW6NSZl5q30DEi2ouT0a8/nj9Q1eTAJcfnuLjqqQNm8t KhInuEA/g+VOF12nWxUr3U67vXAnJD4x43lngcWWmAtpJxz7L4UEnf17c/mZobCMCYOjh1 eUl4WdSopd983/pZttCrdoxuTWdzrcA= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-167-Ms8xgqHYPg29FvkGKzDYAg-1; Mon, 24 Oct 2022 15:43:02 -0400 X-MC-Unique: Ms8xgqHYPg29FvkGKzDYAg-1 Received: by mail-qv1-f69.google.com with SMTP id q17-20020a056214019100b004b1d3c9f3acso5818556qvr.0 for ; Mon, 24 Oct 2022 12:43:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=aS4yi1vMu6K7Mzb0dwDEe+zwP7hRRYhJ4HxVAVJl5ro=; b=QtBWzCfWOrPCOaWK5RLEuf3c/tverQg9SOZQuuNrRX43BW62tFA5dX8ln9xV0iz1r5 TR2396w/KTO/mWsQf+IME3DarIt5rfbteQFXl/KXlDsrjHVjwGZMX8J5ejCLrtxSXKsP hi0OlOLpR0SUV8MnwF2O3UFAS/+RZh5QE2I+VEHeOiD3iFQVNndsvM1hMUXf7PhQTNKT 8Cg6l6XcjAADUyR1Uxm9Xg1NIJaYgtJ4BkxbBCPqOnPKbgLsT3L9ALnApJ8je2AK5mN9 MyGlu/GBBWfq0XZgAyKLjnwc3IACso2OQvfmV6wubBhPpKAZOe5W0/iZp5u7hvaIqk5M 5n1w== X-Gm-Message-State: ACrzQf28BAQaOEO57khnlfBHHT69dmma72nf1qB1tuwy5qZBXJSD94Hc IPQE6rtbOz0vDgtnmmibjiiM4blNJdzAfUiAsvryeatf7CnRs+jdlIHTv4RBtrucxucPUZePAZW wPT06L9LBOmm4gmut0XhwFw8n X-Received: by 2002:a37:64d0:0:b0:6ec:534b:d20e with SMTP id y199-20020a3764d0000000b006ec534bd20emr24544536qkb.491.1666640581833; Mon, 24 Oct 2022 12:43:01 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5HG4hPuNw+OrKVY7aj1+sC0sBSEP1h08iDsLmFF9r5v1x56LUQQ3QNpwRFzoTNCyuX90ew0A== X-Received: by 2002:a37:64d0:0:b0:6ec:534b:d20e with SMTP id y199-20020a3764d0000000b006ec534bd20emr24544518qkb.491.1666640581591; Mon, 24 Oct 2022 12:43:01 -0700 (PDT) Received: from x1n (bras-base-aurron9127w-grc-46-70-31-27-79.dsl.bell.ca. [70.31.27.79]) by smtp.gmail.com with ESMTPSA id bn1-20020a05620a2ac100b006ce3cffa2c8sm521364qkb.43.2022.10.24.12.43.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Oct 2022 12:43:01 -0700 (PDT) Date: Mon, 24 Oct 2022 15:42:59 -0400 From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Axel Rasmussen , Andrew Morton , Andrea Arcangeli , Nadav Amit Subject: Re: [PATCH 1/2] mm/uffd: Fix vma check on userfault for wp Message-ID: References: <20221024193336.1233616-1-peterx@redhat.com> <20221024193336.1233616-2-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221024193336.1233616-2-peterx@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 24, 2022 at 03:33:35PM -0400, Peter Xu wrote: > We used to have a report that pte-marker code can be reached even when > uffd-wp is not compiled in for file memories, here: > > https://lore.kernel.org/all/YzeR+R6b4bwBlBHh@x1n/T/#u > > I just got time to revisit this and found that the root cause is we simply > messed up with the vma check, so that for !PTE_MARKER_UFFD_WP system, we > will allow UFFDIO_REGISTER of MINOR & WP upon shmem as the check was wrong: > > if (vm_flags & VM_UFFD_MINOR) > return is_vm_hugetlb_page(vma) || vma_is_shmem(vma); > > Where we'll allow anything to pass on shmem as long as minor mode is > requested. > > Axel did it right when introducing minor mode but I messed it up in > b1f9e876862d when moving code around. Fix it. > > Cc: Axel Rasmussen > Fixes: b1f9e876862d ("mm/uffd: enable write protection for shmem & hugetlbfs") Should also have had: Cc: stable@vger.kernel.org > Signed-off-by: Peter Xu -- Peter Xu