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=-14.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 A1759C4332D for ; Fri, 20 Mar 2020 19:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AFE320767 for ; Fri, 20 Mar 2020 19:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="fovlzP2k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbgCTTcU (ORCPT ); Fri, 20 Mar 2020 15:32:20 -0400 Received: from mail-oi1-f194.google.com ([209.85.167.194]:42274 "EHLO mail-oi1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726783AbgCTTcU (ORCPT ); Fri, 20 Mar 2020 15:32:20 -0400 Received: by mail-oi1-f194.google.com with SMTP id 13so7742905oiy.9 for ; Fri, 20 Mar 2020 12:32:19 -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=WtK/7/gXu1ovNCUySDq9BYUWoCn1Zjd42Y2kES4LIpM=; b=fovlzP2kOwipRtJHpoxJ4jgC/JCVK0QLiorzypspFTH9aJXj7PP4ZRdxMDg411kk0y a8vWAbRH6LU0oot2ZyauWnBxhQiTxn6JzAGRgfLDcW6ARrVgOYN+0MqnvLvIXoOh5E1X GxdCs7wFLTW24dfgVy0QKYr771PI+xbNkbyJMpUuq6nSdp28lOu1DHxUbJloKhRqili7 pQp1KmfqpwhFPm+wVRq1/uWbhrxaCX9LUutEIkZKtwhJM4hs3GR9FWuPDmqkh040SWxW kIvraYUVo1kk9GLHhQLGaiQWCPK1Wpmw2Z5Ph4v/kSzQ3pTB1OFW7jglZSrPZURI2Eod umWQ== 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=WtK/7/gXu1ovNCUySDq9BYUWoCn1Zjd42Y2kES4LIpM=; b=OTxO+797+n/+jrpPbGLKvXReVKK20V9UDuehbde3zvwpbqKvABMdsVo6pj+8P42WM/ 9ev1GGyrAVI7szC4USRmPEANSgUZSGcblQcC2i6o943LE3hKHVbiCvx2SOz50O99Wl2y f8kY6wuXOzkJ8NnQRumD8l+nQU6sUpBJRzkM6jfu/xXFmDhSdvjoYPH939yxjy5eTwZU n5e9R+W9EgZmAAvIZcOXGKjyjkpE9Klm1OY28NPUwuDvu/NftiS8j2zJMNoePGHMTBlZ aW5JhUhGewWQBWwQNmqyUXa2/kvrbQOMMsQM2JW5V/ngAV6wiM6My9A2bzIWu2L2MX0I 07eA== X-Gm-Message-State: ANhLgQ2zyy2ruFu1tCYBRnSN0dVrXVDS9ZZyaFXBnybeqduDeNsxHEEv CFUoyWln2LriBc0AXF1YvpZpUxD22Mm8psIP0SgqvA== X-Google-Smtp-Source: ADFU+vtATW7OF0jdQrbPsEIZUB6+NQzlm/MoxyVX81FQyBfsxlRimzKyzb8W88GR0NPdrdcTifvl4fObC6qNPQQvkIc= X-Received: by 2002:aca:5d83:: with SMTP id r125mr2660083oib.8.1584732739064; Fri, 20 Mar 2020 12:32:19 -0700 (PDT) MIME-Version: 1.0 References: <20200313223920.124230-1-almasrymina@google.com> <87zhcin6gr.fsf@redhat.com> In-Reply-To: <87zhcin6gr.fsf@redhat.com> From: Mina Almasry Date: Fri, 20 Mar 2020 12:32:07 -0700 Message-ID: Subject: Re: [PATCH -next] hugetlb_cgroup: fix illegal access to memory To: Giuseppe Scrivano Cc: syzbot , Andrew Morton , Linux-MM , open list , Tejun Heo , Mike Kravetz , David Rientjes 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 Tejun/Mike you want to also give this a quick look? On Sat, Mar 14, 2020 at 11:21 AM Giuseppe Scrivano wrote: > > Mina Almasry writes: > > > On Fri, Mar 13, 2020 at 3:39 PM Mina Almasry wrote: > >> > >> This appears to be a mistake in commit faced7e0806cf ("mm: hugetlb > >> controller for cgroups v2"). Essentially that commit does > >> a hugetlb_cgroup_from_counter assuming that page_counter_try_charge has > >> initialized counter, but if page_counter_try_charge has failed then it > >> seems it does not initialize counter, so > >> hugetlb_cgroup_from_counter(counter) ends up pointing to random memory, > >> causing kasan to complain. > >> > >> Solution, simply use h_cg, instead of > >> hugetlb_cgroup_from_counter(counter), since that is a reference to the > >> hugetlb_cgroup anyway. After this change kasan ceases to complain. > >> > >> Signed-off-by: Mina Almasry > >> Reported-by: syzbot+cac0c4e204952cf449b1@syzkaller.appspotmail.com > >> Fixes: commit faced7e0806cf ("mm: hugetlb controller for cgroups v2") > >> Cc: Andrew Morton > >> Cc: linux-mm@kvack.org > >> Cc: linux-kernel@vger.kernel.org > >> Cc: Giuseppe Scrivano > >> Cc: Tejun Heo > >> Cc: mike.kravetz@oracle.com > >> Cc: rientjes@google.com > >> > >> --- > >> mm/hugetlb_cgroup.c | 3 +-- > >> 1 file changed, 1 insertion(+), 2 deletions(-) > >> > >> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c > >> index 7994eb8a2a0b4..aabf65d4d91ba 100644 > >> --- a/mm/hugetlb_cgroup.c > >> +++ b/mm/hugetlb_cgroup.c > >> @@ -259,8 +259,7 @@ static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, > >> __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd), > >> nr_pages, &counter)) { > >> ret = -ENOMEM; > >> - hugetlb_event(hugetlb_cgroup_from_counter(counter, idx), idx, > >> - HUGETLB_MAX); > >> + hugetlb_event(h_cg, idx, HUGETLB_MAX); > >> css_put(&h_cg->css); > >> goto done; > >> } > >> -- > >> 2.25.1.481.gfbce0eb801-goog > > Acked-by: Giuseppe Scrivano > > Thanks, > Giuseppe >