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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 BAA75C433F5 for ; Wed, 29 Aug 2018 18:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A09E2064E for ; Wed, 29 Aug 2018 18:56:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OC7iT4DR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A09E2064E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728224AbeH2WyY (ORCPT ); Wed, 29 Aug 2018 18:54:24 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:37710 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727988AbeH2WyY (ORCPT ); Wed, 29 Aug 2018 18:54:24 -0400 Received: by mail-pg1-f196.google.com with SMTP id 2-v6so2198214pgo.4; Wed, 29 Aug 2018 11:56:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=NDrzUZm901/nMcWqi36Qs4oyeMMxHJABu56mgrU/GkE=; b=OC7iT4DRMK47M+AZyzGcibBIjHAmCWGCMVWXXlIpa8V2l39RPqc84HnIKvz91g7jRn 9BJZic949aAEWV0o+cm24iKkeftFnWJyw0fFi/r2LJ2tiKvhnORTm69cag2vZEjRi1zF F1UjPwfzvvQFJoBefIY2aRVO4PNVmkHA+UXTSobaT4kbcRf5czE8RWtZyQ4BGZj60IfO ZHfGeRe+NMHGOkYrsXglkw5tTN2xvch4zqGcL3s0FIOwRUe7kxk6hsaOTPUdkvFaM1yu AUfX9UjB8xu4/R78wKrjog3zAaMUORtXiKZn6228hOeZNPdvcllpVCRweJ91rIhegrmh V7BA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=NDrzUZm901/nMcWqi36Qs4oyeMMxHJABu56mgrU/GkE=; b=js9+SDNHQ3UkKzNWR7/pJjLpvJv7wezVI5m6Ekr1zPaBWkTptLzB7u4uqwLb3dZHx6 1sLpp2SILqgq1PUTEj4f+NFTv5o0GI7YdpwMx4DVz3/y8soVTOSLOtYsLPM4icqu/5RW FjWkSWuewL0TFQsTjvnabMUorZ5IVDGf5AonuYab11Wy2U3Js7xKQSRGsaJo4Gc/d0fZ rLeBmlGBFsDY1h+GD5mNUGmt+RKgdRIf13iG8J+gP+hPPUtCvwlGhTCvNNmfC8ICA90i ohguw+N+FgMDif4hldviiNuXmRnJ4C2tSQwmMJBjpszeSp4NZUeO0vDr26Ij90PvfVbR 7q+Q== X-Gm-Message-State: APzg51AhGqa/PXaigp4edKoVgE3RwOE1M4nNlKnPHXck4D6MBvndI4d/ ZvEALJyh3Ov2VcxDBkKKn3iYtav5 X-Google-Smtp-Source: ANB0Vdbqdbzx3J5UpcidWW3s/m7Vb5yqdmtfpkpl6ZfoKtuYKMDLUnUjisogPnhK8786GSdRUXYTeQ== X-Received: by 2002:a62:990f:: with SMTP id d15-v6mr7185901pfe.162.1535568970956; Wed, 29 Aug 2018 11:56:10 -0700 (PDT) Received: from [10.33.114.204] ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id z6-v6sm6546556pgr.41.2018.08.29.11.56.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 Aug 2018 11:56:10 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: [PATCH v2] x86/nmi: Fix some races in NMI uaccess From: Nadav Amit In-Reply-To: Date: Wed, 29 Aug 2018 11:56:08 -0700 Cc: Borislav Petkov , Rik van Riel , Jann Horn , LKML , stable@vger.kernel.org, Peter Zijlstra Content-Transfer-Encoding: 7bit Message-Id: <7202F39D-B4C2-4FA0-868E-2D03BD313BD7@gmail.com> References: To: Andy Lutomirski , x86@kernel.org X-Mailer: Apple Mail (2.3445.9.1) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org at 8:47 AM, Andy Lutomirski wrote: > In NMI context, we might be in the middle of context switching or in > the middle of switch_mm_irqs_off(). In either case, CR3 might not > match current->mm, which could cause copy_from_user_nmi() and > friends to read the wrong memory. > > Fix it by adding a new nmi_uaccess_okay() helper and checking it in > copy_from_user_nmi() and in __copy_from_user_nmi()'s callers. > > Cc: stable@vger.kernel.org > Cc: Peter Zijlstra > Cc: Nadav Amit > Signed-off-by: Andy Lutomirski > --- > > Nadav, this is intended for your series. Want to add it right > before the use_temporary_mm() stuff? Sure. Thanks! I will apply the following small fix: > + > +#ifdef CONFIG_DEBUG_VM > + WARN_ON_ONCE(!loaded_mm); > +#endif Will be changed to VM_WARN_ON_ONCE() in the two instances. Regards, Nadav