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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 529E1C43603 for ; Wed, 4 Dec 2019 20:37:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 161E12077B for ; Wed, 4 Dec 2019 20:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575491837; bh=zpttg4wTmrnmWgU+meM5WiRudYKWetdf+Ntkr9iOltw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=GNOlEVWJ/cpFoow21xb2pV4TRaaMiDqIIkfim7wuHquU6eDUiplaeDcLPDrw9jTdy SzH2oCjf4trLfurjnsf2bifHzKXlqBKpYf2mpONFtsk0plqaNifHOJQRcJ8VssksVK tsyHbIIOk1opcAfTkT23OX3JV3V6m7LTJYzdVTB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728042AbfLDUhQ (ORCPT ); Wed, 4 Dec 2019 15:37:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:45330 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727911AbfLDUhQ (ORCPT ); Wed, 4 Dec 2019 15:37:16 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 561702073B; Wed, 4 Dec 2019 20:37:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575491835; bh=zpttg4wTmrnmWgU+meM5WiRudYKWetdf+Ntkr9iOltw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=USu9K8erfGC8SMJC/MfMFdcIf1GKAZkQOFnddGA30OdAYK+wWmqkyQ4B4z4VWfkZW RoiaCwzQJbBwKAbypjfdQIoMePdJWgqr92eDLe1cwxM05mwAsyr1/nIhuJgU9v5El4 RcAibY98n3unHuw0IhgV5UM3t6pTIyWHzI25fciM= Date: Wed, 4 Dec 2019 21:37:11 +0100 From: Greg Kroah-Hartman To: Vlastimil Babka Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sasha Levin , Ben Hutchings Subject: Re: [PATCH 4.9 105/125] mm, gup: add missing refcount overflow checks on x86 and s390 Message-ID: <20191204203711.GA3685601@kroah.com> References: <20191204175308.377746305@linuxfoundation.org> <20191204175325.500930880@linuxfoundation.org> <7ca516fa-c526-b5e6-4b7c-855f229112ac@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7ca516fa-c526-b5e6-4b7c-855f229112ac@suse.cz> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Dec 04, 2019 at 07:27:44PM +0100, Vlastimil Babka wrote: > On 12/4/19 6:56 PM, Greg Kroah-Hartman wrote: > > From: Vlastimil Babka > > > > The mainline commit 8fde12ca79af ("mm: prevent get_user_pages() from > > overflowing page refcount") was backported to 4.9.y stable as commit > > 2ed768cfd895. The backport however missed that in 4.9, there are several > > arch-specific gup.c versions with fast gup implementations, so these do not > > prevent refcount overflow. > > > > This is partially fixed for x86 in stable-only commit d73af79742e7 ("x86, mm, > > gup: prevent get_page() race with munmap in paravirt guest"). This stable-only > > commit adds missing parts to x86 version, as well as s390 version, both taken > > from the SUSE SLES/openSUSE 4.12-based kernels. > > > > The remaining architectures with own gup.c are sparc, mips, sh. It's unlikely > > the known overflow scenario based on FUSE, which needs 140GB of RAM, is a > > problem for those architectures, and I don't feel confident enough to patch > > them. > > > > Signed-off-by: Vlastimil Babka > > Signed-off-by: Sasha Levin > > No, this one had a leak bug and I've sent updated version: > https://lore.kernel.org/linux-mm/e274291b-054f-2fad-28e8-59fabf312e61@suse.cz/ Ugh. Ok, let me go fix that up...