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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 2938DC65BAF for ; Thu, 6 Dec 2018 21:33:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF00B20989 for ; Thu, 6 Dec 2018 21:33:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF00B20989 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.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 S1726187AbeLFVcs (ORCPT ); Thu, 6 Dec 2018 16:32:48 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41154 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726200AbeLFVcY (ORCPT ); Thu, 6 Dec 2018 16:32:24 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wB6LToPu138628 for ; Thu, 6 Dec 2018 16:32:22 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2p7bdd92gg-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 06 Dec 2018 16:32:22 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 6 Dec 2018 21:32:16 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wB6LWF5v64815120 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 6 Dec 2018 21:32:15 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B446C42045; Thu, 6 Dec 2018 21:32:15 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7DDC542042; Thu, 6 Dec 2018 21:32:14 +0000 (GMT) Received: from rapoport-lnx (unknown [9.148.206.110]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 6 Dec 2018 21:32:14 +0000 (GMT) Date: Thu, 6 Dec 2018 23:32:12 +0200 From: Mike Rapoport To: Andrea Arcangeli Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Mike Rapoport , Mike Kravetz , Jann Horn , Peter Xu , "Dr. David Alan Gilbert" Subject: Re: [PATCH 1/1] userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered References: <20181206212028.18726-1-aarcange@redhat.com> <20181206212028.18726-2-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181206212028.18726-2-aarcange@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 18120621-0020-0000-0000-000002F3A712 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18120621-0021-0000-0000-00002143B9BB Message-Id: <20181206213212.GB7479@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-12-06_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812060180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 06, 2018 at 04:20:28PM -0500, Andrea Arcangeli wrote: > Calling UFFDIO_UNREGISTER on virtual ranges not yet registered in uffd > could trigger an harmless false positive WARN_ON. Check the vma is > already registered before checking VM_MAYWRITE to shut off the > false positive warning. > > Cc: > Fixes: 29ec90660d68 ("userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas") > Reported-by: syzbot+06c7092e7d71218a2c16@syzkaller.appspotmail.com > Signed-off-by: Andrea Arcangeli Acked-by: Mike Rapoport > --- > fs/userfaultfd.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index cd58939dc977..7a85e609fc27 100644 > --- a/fs/userfaultfd.c > +++ b/fs/userfaultfd.c > @@ -1566,7 +1566,6 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, > cond_resched(); > > BUG_ON(!vma_can_userfault(vma)); > - WARN_ON(!(vma->vm_flags & VM_MAYWRITE)); > > /* > * Nothing to do: this vma is already registered into this > @@ -1575,6 +1574,8 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, > if (!vma->vm_userfaultfd_ctx.ctx) > goto skip; > > + WARN_ON(!(vma->vm_flags & VM_MAYWRITE)); > + > if (vma->vm_start > start) > start = vma->vm_start; > vma_end = min(end, vma->vm_end); > -- Sincerely yours, Mike.