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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9E6CDC5DF60 for ; Tue, 5 Nov 2019 15:29:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6DA8A214B2 for ; Tue, 5 Nov 2019 15:29:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DA8A214B2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EFFD46B0008; Tue, 5 Nov 2019 10:29:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ED6A06B000A; Tue, 5 Nov 2019 10:29:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D9F136B000C; Tue, 5 Nov 2019 10:29:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0035.hostedemail.com [216.40.44.35]) by kanga.kvack.org (Postfix) with ESMTP id C73C06B0008 for ; Tue, 5 Nov 2019 10:29:52 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 8DF1D180AD802 for ; Tue, 5 Nov 2019 15:29:52 +0000 (UTC) X-FDA: 76122609024.21.town84_73422bc4e6209 X-HE-Tag: town84_73422bc4e6209 X-Filterd-Recvd-Size: 4289 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Tue, 5 Nov 2019 15:29:51 +0000 (UTC) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xA5FSD0G108780 for ; Tue, 5 Nov 2019 10:29:50 -0500 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w3a4h59a3-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 05 Nov 2019 10:29:50 -0500 Received: from localhost by e06smtp02.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) Tue, 5 Nov 2019 15:29:41 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xA5FTeZZ55640148 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 5 Nov 2019 15:29:40 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CE50AA4051; Tue, 5 Nov 2019 15:29:40 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BAB3CA404D; Tue, 5 Nov 2019 15:29:38 +0000 (GMT) Received: from rapoport-lnx (unknown [9.148.8.59]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 5 Nov 2019 15:29:38 +0000 (GMT) Received: by rapoport-lnx (sSMTP sendmail emulation); Tue, 05 Nov 2019 17:29:38 +0200 From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Andrea Arcangeli , Andrew Morton , Andy Lutomirski , Daniel Colascione , Jann Horn , Linus Torvalds , Lokesh Gidra , Nick Kralevich , Nosh Minwalla , Pavel Emelyanov , Tim Murray , linux-api@vger.kernel.org, linux-mm@kvack.org, Mike Rapoport Subject: [PATCH 0/1] userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK Date: Tue, 5 Nov 2019 17:29:36 +0200 X-Mailer: git-send-email 2.7.4 X-TM-AS-GCONF: 00 x-cbid: 19110515-0008-0000-0000-0000032AEF58 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19110515-0009-0000-0000-00004A4A4A16 Message-Id: <1572967777-8812-1-git-send-email-rppt@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-05_05:,, 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=808 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911050127 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, A while ago Andy noticed [1] that UFFD_FEATURE_EVENT_FORK used by an unprivileged user may have security implications. As the first step of the solution the following patch limits the availably of UFFD_FEATURE_EVENT_FORK only for those having CAP_SYS_PTRACE. The usage of CAP_SYS_PTRACE ensures compatibility with CRIU. Yet, if there are other users of non-cooperative userfaultfd that run without CAP_SYS_PTRACE, they would be broken :( [1] https://lore.kernel.org/lkml/CALCETrWY+5ynDct7eU_nDUqx=okQvjm=Y5wJvA4ahBja=CQXGw@mail.gmail.com Mike Rapoport (1): userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK fs/userfaultfd.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) -- 2.7.4