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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 C7817C433E1 for ; Sat, 15 Aug 2020 21:59:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A878020791 for ; Sat, 15 Aug 2020 21:59:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="G+MiGLci" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729564AbgHOV7D (ORCPT ); Sat, 15 Aug 2020 17:59:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728933AbgHOVvy (ORCPT ); Sat, 15 Aug 2020 17:51:54 -0400 Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48817C0F26DB for ; Sat, 15 Aug 2020 10:39:11 -0700 (PDT) Received: by mail-io1-xd41.google.com with SMTP id z6so13748318iow.6 for ; Sat, 15 Aug 2020 10:39:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AwnENJtZcTDyRowOll9BqELCaHCpWYH0qCJCKyyi9Wk=; b=G+MiGLcif5DCcsQJ7v2ioepIk6jXx5VRMkgMKoSkPKhCM4uqzvts04XWodlwFzeY5P NclSMUl/w2hiXLcpbvaHWDJ3TdUG3jGO7uBwVI8lfbydMVUWKiY402fO91FHJi0vSU5c WA2Yft+iACB/ch7aP/l2qYtTWJ2pIatVRYrW2gQWzarBzNE9HjmYmrToCQdlCxAITkW6 G9NIxIJkcTF6oR47dFXvAMZUTbFjzdtm7B/V4cLhQuz3R/HavtviwDymE0n6M1QdLSKc PyXrmsGq+f8JQhJ9L4n4f1SLD8PHDuP3Ch66CLzVYWSaHT4Q4r1dhzDLQfH2MovQAowX xLgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AwnENJtZcTDyRowOll9BqELCaHCpWYH0qCJCKyyi9Wk=; b=nz9Z9vUyMsUBvbjJS/Y7jthTFOCXjojdR0z72NNZBzWQoVcrfB0xibIH7jEy9wkCEA 4DLw6WFTAf369M6POEORVQMR2Xmqef8gu+OJfz2f4xdrriMaX8pP/j77Ejlnllb6sf5U 8n+jJeVhFb2mRFYGs02jfywhbDL0s18jp1NGF+/wGNLAT5jeCGzjLB4eSPIl/tTuFZUm 38OHnsjeQdR39GX/UEFXiSCz95ADB7fYbLC48sroAuSUiwZJzUOoKvOPzUDqv+zebOLp +rt17izw2s5JtwwWu7XSAqlx8WFrLr6c/CHQ3oqk818VJRNE0gzGqZKYHxg1S7D84ns3 Mytg== X-Gm-Message-State: AOAM530WM9Gvfob8//rwB8qDW8H5qANDO2M/LCgJtBLuYGDD8CdyWxC4 Y/c7q5+sRyxWP9dCenadaX0WV0lipc5cQGvUIvZcvQ== X-Google-Smtp-Source: ABdhPJzcRPuzpUvOUtSTbfV6H5JUuJ16ZCQDnG3mf/q7oZEvlSW4uCbycbflqCY6ehJZuh/YEjgTFlhz2kN8M+lj1NY= X-Received: by 2002:a5d:9d8a:: with SMTP id 10mr6650437ion.195.1597513149676; Sat, 15 Aug 2020 10:39:09 -0700 (PDT) MIME-Version: 1.0 References: <20200814181617.442787-1-edumazet@google.com> <20200815114825.GA2685004@gmail.com> In-Reply-To: <20200815114825.GA2685004@gmail.com> From: Eric Dumazet Date: Sat, 15 Aug 2020 10:38:58 -0700 Message-ID: Subject: Re: [PATCH] x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task To: Ingo Molnar Cc: linux-kernel , Eric Dumazet , Jann Horn , syzbot , Andy Lutomirski , "Chang S . Bae" , Andy Lutomirski , Borislav Petkov , Brian Gerst , Dave Hansen , Denys Vlasenko , "H . Peter Anvin" , Linus Torvalds , Markus T Metzger , Peter Zijlstra , Ravi Shankar , Rik van Riel , Thomas Gleixner Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 15, 2020 at 4:48 AM Ingo Molnar wrote: > > > * Eric Dumazet wrote: > > > syzbot found its way in 86_fsgsbase_read_task() [1] > > > > Fix is to make sure ldt pointer is not NULL. > > Thanks for this fix. Linus has picked it up (inclusive the typos to > the x86_fsgsbase_read_task() function name ;-), it's now upstream > under: > > 8ab49526b53d: ("x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task") > > By the fixes tag it looks like this should probably be backported all > the way back to ~v4.20 or so? This is absolutely right, sorry about the lack of a stable tag. Most of my patches usually land into David Miller trees, where the stable tag is not welcomed. We use Fixes: tags to convey the exact information needed for stable backports. Thanks.