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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 859F2C2BAEE for ; Tue, 24 Mar 2020 18:25:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6278020714 for ; Tue, 24 Mar 2020 18:25:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585074300; bh=BRk1zWa2KIAD8ZVBGXTm/WReYp6lXgOaW2wcIaRZ5RE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=UsSkZKHYpiOiM93jkVXtPza6uVAozpNEL8ByWcF4PeRFHW1ukBIIsfWFR1BW82DpN OCK/s7kF0oSbbp1JeNAAaCCBnGzECx6VzJ2WfiOt/kcXaQn+y1sfZJw4GyAxGWCT6/ KidK9OUdeE5RdHT3Rz9kwnuirWAYA1xHEbpxsevk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727696AbgCXSY7 (ORCPT ); Tue, 24 Mar 2020 14:24:59 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:33809 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727333AbgCXSY7 (ORCPT ); Tue, 24 Mar 2020 14:24:59 -0400 Received: by mail-qk1-f196.google.com with SMTP id i6so11253878qke.1 for ; Tue, 24 Mar 2020 11:24:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=RconwbLGvobrkQrLA8HZT5QCPO0hEEsGfTPRzr6x1ls=; b=qWQ0JOE3fCDg+RdT+hVndA3MY+mCBruUcX/KRXX1erbOlMR8BmWY+rmW0XC5KEltTK Esqctl8cGeg6M5mbdM8kJg6O7WkZBUw3rNFBdmELweVdBaRROiXkV4Idm8F4A2Xw8FGn codkCjZJZWnEcuySG4NFSH1GOpywlWqjp/ZObBdqDN8LWcvTkIpYJySbrrlqjHUJVnMK 6B1SmqHfjnjazYbnBSmOXN1FZ9FQHMPPeavkMV5IlGpVuubHIlf9/n0dhUS8aE/UTp9h ykQLr1yTU0sskkIulH6GAJcxxy6mDya6Pta2xnH7x6y56Jqqh4TVShb+eO9r1Ar3lO9I awnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=RconwbLGvobrkQrLA8HZT5QCPO0hEEsGfTPRzr6x1ls=; b=L91GKKCz53WW+mDRrymWsYG/yI8iHBvmbY6B0JCaTNT03Py6/RtVpSAcRAQQtC66Nc blHXOfE088xs2N7bMoidaLX+IA/1jDXngFGnJvpYpUG7hX22nIMb8RiaPlpxq/ah5Nni Eg1g5d6+VTWwUcRRQgA8uo2EdSVphI9MhJfIfIMo6/QPgdFNy/UkKfiKDWIuYV9UToDZ 6yRwRZKwvBNya3XXq4bp+hOkdRSrkPSQ/IkdhQRGsSX4X0AjXMzV2WGMKUMngMJRU23A eyAMs17ulXz1ABIAwT7pur/uxDcO6WVsKLOS1c8XNBrlYBxB9YKCIWWJC3BoUvscFtrf T7XQ== X-Gm-Message-State: ANhLgQ1AB78tbm0MhkirD/6xhu7KLLDqEd9oTbtHZOdDg0TBto/SGU9g miGEL3cOpf+msi2UI9DCZww= X-Google-Smtp-Source: ADFU+vtqLe2wnw4h8YDpEepGFhKK7We9Rhe1ZxfEVlqXh61lSnV6dWCn407Z4KLJK4FVGOuzufntxQ== X-Received: by 2002:a37:91c3:: with SMTP id t186mr26109176qkd.239.1585074296754; Tue, 24 Mar 2020 11:24:56 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::19c2]) by smtp.gmail.com with ESMTPSA id h5sm13514266qkc.118.2020.03.24.11.24.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Mar 2020 11:24:56 -0700 (PDT) Date: Tue, 24 Mar 2020 14:24:54 -0400 From: Tejun Heo To: Mina Almasry Cc: syzbot+cac0c4e204952cf449b1@syzkaller.appspotmail.com, Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Giuseppe Scrivano , mike.kravetz@oracle.com, rientjes@google.com Subject: Re: [PATCH -next] hugetlb_cgroup: fix illegal access to memory Message-ID: <20200324182454.GE162390@mtj.duckdns.org> References: <20200313223920.124230-1-almasrymina@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200313223920.124230-1-almasrymina@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 13, 2020 at 03:39:20PM -0700, 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 Acked-by: Tejun Heo Thanks. -- tejun