Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <7354132e-c09b-ac41-add5-116b79bc1a4a@oracle.com>
Date:   Thu, 6 Oct 2022 10:29:34 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.2.2
Subject: Re: [GIT PULL] LSM patches for v6.1
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Paul Moore <paul@paul-moore.com>,
        linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org
References: <CAHC9VhShpEVTuogj4h74PxbEeTUNn4odo8SE6GBvb6sGUM0LHw@mail.gmail.com>
 <87sfk3mim9.fsf@email.froward.int.ebiederm.org>
 <CAHk-=wiCqicQrnQPeHbDF7ECKHk_ceYzZK5dYq7y5nZTZhpB8g@mail.gmail.com>
Content-Language: en-US
From:   Vegard Nossum <vegard.nossum@oracle.com>
In-Reply-To: <CAHk-=wiCqicQrnQPeHbDF7ECKHk_ceYzZK5dYq7y5nZTZhpB8g@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QWNZVlZvQ3VjZXpRa1UvR0JSOXBIZE1lM0d2TGs4ODRTV1MyV25xdXV1aWdU?=
 =?utf-8?B?T0ZvVlRjQlhNUjY5REpnVFlJdEdvMnVaclFDUkp6amo0QktvQTYzS002RzF5?=
 =?utf-8?B?K2Z2NWZFRnJvYklndUlYdldhc25ORnZ5M0thbzdZdXJBaUdQOVN6N3UwY2pH?=
 =?utf-8?B?cGlBZDVLL1ZSOWNkVzNxMmNadzFpc3FGUjhXNGFUTnpIeC83OENHaFF3K1ZF?=
 =?utf-8?B?bHRFNG9BbytPdDZSQW5hTkxtcDlaRFBxS2t0TWZtc1hLWUtYUHBRdm5XU1hU?=
 =?utf-8?B?MzlETHVWY0FHWUd3Mm9aN2ovVjIxcFJVSEhEck04aWlSd0JjM1pwNE1zMm9v?=
 =?utf-8?B?NmdQNldkbUI2aDNxd0lXdEYrVWNycFNjazRrbTR1SW0xQVJqRmowVlpqY2xp?=
 =?utf-8?B?MDVVQzZjemxYL3VrZXNUd2VYelFXTEpMd0gwdkZpeHQwUkdqcUwvSmkrOHNL?=
 =?utf-8?B?dXdURlF1NmtNL3JpL014d2YzWnI4MVVRa2dPMHJCYmJUMXBaMEFhNjhkT3Bn?=
 =?utf-8?B?NmRySDlTS0YyZFQrckIwUDFiUkt4a1ZxZW9BNkE1cGkvQUVwTG1CdUlDWXRE?=
 =?utf-8?B?bHovU1VYT0N6OUpBdzY3Z2JDZDRIT2xMUGpITXB0SG5qRlhkbExvVDQ4blZ2?=
 =?utf-8?B?QmNaVlBKNEdTTi93NFUyZTlYVWxsaEtCcHQ2NHc5WVRlZVduQWhnMVkySTVm?=
 =?utf-8?B?OFJacktKUXptdm5WSGVzYjdMM2dFODFibnViSklmOUp6NDAzRWpBRmpER01X?=
 =?utf-8?B?cVhXai9OTjJQZkovSVJmVnh2ZU4wK3EyN1BoUGt5bm0waUYweW91SHV0VlJp?=
 =?utf-8?B?aHBGYzhXZXlQeE1CV1B1Q2ptRm05NTBMN3hiZENuRTg2ZFRrR0JDWm96ZHRB?=
 =?utf-8?B?ZmM5NzN0bEprdWRqWTFnczNwRTd5VDlrM2RZSXdrUEZjWXpTdnNnREpNbExI?=
 =?utf-8?B?QjlLYTRKVmFCcDZBNUkwSlgxdDBsZ2FYS05ocXh4dHl6dnN0S0l2YWZJbVhD?=
 =?utf-8?B?OUthb25kS2liL0dRNlVmWm1HaVdxalYxUnpLbk5wNWZmVXVkQ2s5VzZZSU13?=
 =?utf-8?B?ZGg0UWRWU3ZOWVNKM1JjRzNmNXQrdEQ2RlhrZ1JRTHV0cVkyTm5WNmFiYVhw?=
 =?utf-8?B?TTlBT3lkOXp2SEZvRWZqMzcrckFUMVltWHRReFNqdnlKZENRazRscWlSMWVM?=
 =?utf-8?B?Mm1waUplUnVydFZSMFlwSUlhRTFNTkhaTkFxMGhySWRscDZzSWJybDQ4RDNO?=
 =?utf-8?B?NzdFRE9CWWxmZmdacitsd0tjSjhtdzhjVDFyejRRK2N5V09sbkJPRFB0YjBX?=
 =?utf-8?B?aStrbHV5WEFmTjdUQk5pK1NnbWovY2c3czFvS3JMTWc3aUdwSDh5THB0ckVF?=
 =?utf-8?B?bTVHQ25lakYxYnFQQStoRWJCMzVwU0tpOG9sWjBXTHBxLzJYVG83QXc5UWtM?=
 =?utf-8?B?aU9Pa3V3aTNHSXhxQ0ZjTjVkQjh2VlhoMkVseWNOdG5RNHJ5eXVBYWNpdHlZ?=
 =?utf-8?B?YUg0VWUwWHVYTDcxSFN1Mm1WQklBajdTK242eUNEbS9wK0g5S3dEZlB3ZTh4?=
 =?utf-8?B?K0dZVVZRSDBiTjlLSXVQRDhDSlZRdzVyaytxQ0dkSWNmV0NRS3FnZUdzMmZN?=
 =?utf-8?B?MTFWOGQ1MlEwSzNQSzU2QXNqdEhDRHdja0F4R04yMHRnTmtBVUFhcVNQSE1C?=
 =?utf-8?B?OGdORUtyckFyWjFXM2lKWnhoTkx6QzY0Sm9CR3UwNHhsVDhMdUZKNDBVbDRk?=
 =?utf-8?B?TEZnVjBYOW04UUpKT0s1T05wNEJvdExPUThmSnBlVmtvRWoxSEhkOUx4K2x3?=
 =?utf-8?B?L1RSUXNuQ2gvY094emFFMnIraVczemUwVk45NjhYOFhXeHpzOG5USGR3blY1?=
 =?utf-8?B?Q0daa1MrUGNaSjJTaEVEY1NxTmtnc2R0TG4zSk5pWUhyTjR5RWdsRS95dEph?=
 =?utf-8?B?RzcyYjM0eU1RMEI4Yy81eUdqUk45UEQzRTVJbis0K0tuS0UvSXVUTmhxRmwx?=
 =?utf-8?B?azJaYnhzS3gxUEg1UmFvWHF2aVFiQ3lRU2NWcnVkL0FhY2dGNjIwc0pobC9h?=
 =?utf-8?B?R01VR1kwUXljMk1oblUrcFBnRVZNaUx3TkpYdGxMQkhaSER1cXluR0tIWnkz?=
 =?utf-8?B?WU56Z24xajJhNmNjSm9vNDFMOXYwN0lOczdHSm1RVSsxaUR3eDRlZVBwb3ZG?=
 =?utf-8?B?cHc9PQ==?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?utf-8?B?aGtWSjJDdEEvQWRJeWU5citXTWRHWEQ2WWltT0Fsa0xiNGNIQzdDTE51U0pj?=
 =?utf-8?B?RUhaUXIvZWVtME1wd0U4QWNnYnhNMEJrV3IwZDFsVzFES05oMHRUSU1NcjA0?=
 =?utf-8?B?ZVNkYVVQVEYydEpDNzkxTnhrVWF6SUx4OXNwSngyZXJTTVFodkdSajY2RG1a?=
 =?utf-8?B?RE1SNDYxanMreTR0UG9zSG96enBWdFFza3ZmWGc0bTVGUG9hQUplSHNaVVR0?=
 =?utf-8?B?TkpwejlOZ1JXT1V6TWZuOFgwYWxjbkw3Yk9tQ2t4ZHJUeTZ3blM3b3h2Q0dq?=
 =?utf-8?B?WTlCQUJPWHJuZGc4VDNmYlhLdDNBVnNUWGtTb2ZRZG10VmRmTCtNRDFnTGFy?=
 =?utf-8?B?a3FPQ2Nqdm9NeFBjSitZWHhzR1o2VXRsalNvUm5hcU1tVkVTMTZZbTdwZGdJ?=
 =?utf-8?B?NnpnRk03alNnajNDeUJGQ1pwamtMMldCQTZxQzN3N3F3cUZLbVc2Q2RSVzlo?=
 =?utf-8?B?Z2I3TXRGUGtpaXlsNjRXUncvMHQrbmpVYWx6TTRXaVppREYxdStZaG01dkJq?=
 =?utf-8?B?eXFaNHRqS0k1ZnRpaVRoTzJ0MW9KZWNRVDV0MWlZOWh0amFSSE1RR3hxTFhj?=
 =?utf-8?B?NVBscVdrOWVIMUFwMDBWWVJnOFE1L3h4Nkw5ZjNuZEhrcjlTdkpIQlY1UTUx?=
 =?utf-8?B?SkFmSjYrWGZUd0FxcjMvOEwyWUNhejZEUU1hTDVCWm5ubG9Za0dtOXN5RTFW?=
 =?utf-8?B?YWVSeUtUblVRRlhjQXA1am02NjRHNC9ydURZTWE3aWYvZVJ0cHRjMEovUXo1?=
 =?utf-8?B?dWVsY2E2K09CYmlvU3ZDbGxiN0xWUk9xRzUwQVVwYjl2UHdtRVJkK3Npckk2?=
 =?utf-8?B?QldCTU50K2VkNmdhNWpKeE1ZeWpJRjQ3bzhWNWtzOGdoYktmWmxGekZwVGFH?=
 =?utf-8?B?SHVvNkkvekFpQlRlZEJJUVArL0MwdVdwY2xwUnhnV2g5K083Z0VuazRZM2Zj?=
 =?utf-8?B?aE1jdXRKNjRkNkhaZ29aUjlLVUh0MThzaTRwVGRpRVRzcUdrUlhzSCt2aFAv?=
 =?utf-8?B?eWRwSURCMnE2bGpJUDkrbDZHQ1hIZ0FkTDU4aEtDUVFXbVNHV05NZzcrS1dQ?=
 =?utf-8?B?aFF3NUlXUmNWNUhkWGN0WW1ldnlMNlArbzlTcDVIWWVNQkkxaFZuUnR1UThz?=
 =?utf-8?B?YlJaeFRaQWJpV0hMdS9ZaHFuaUdmdFBYdmZ4MVdhaFNOQzlpWEdGWVF1SXd0?=
 =?utf-8?B?SkMvOTEyai9rR0t4UlRsTUxzalFDUG5jUkRUbVlyTzJ4MENqZVVUZm1aR0RX?=
 =?utf-8?Q?4rWMwqPDN4NDJOX?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: f49825d2-1531-4991-efc8-08daa774ea17
X-MS-Exchange-CrossTenant-AuthSource: PH0PR10MB5433.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Oct 2022 08:29:41.5108
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: oZqmHCvxVIJg0tr/GFcVdIUg+6Dyii/GVLtEuE5xolmwmJ7y24CQ7gFeRGwPcUOExwXo0kQnuMND4oFGQDtkT7Jxu3YbUSeLF060Z52b2fM=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB4767
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1
 definitions=2022-10-05_05,2022-10-06_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 phishscore=0 bulkscore=0
 suspectscore=0 mlxlogscore=999 mlxscore=0 spamscore=0 adultscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000
 definitions=main-2210060050
X-Proofpoint-GUID: h_bWBxGFM9b0KzqJ59T8fhDf7Cyczg3l
X-Proofpoint-ORIG-GUID: h_bWBxGFM9b0KzqJ59T8fhDf7Cyczg3l
X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 10/4/22 22:55, Linus Torvalds wrote:
> And I think you are in denial about how many problems the
> user-namespace stuff has caused.
> 
> Distros are literally turning it off entirely because the whole "let
> users create their own namespace" has *NOT* been a great success.

[...]

> I'm not saying that an LSM is the only place to do it, but I don't
> think there have been any better suggestions either.

I had posted a patch here for restricting module loading requests from
user namespaces as a way to reduce attack surface:

v2: 
https://lore.kernel.org/all/20220815082753.6088-1-vegard.nossum@oracle.com/

v1: 
https://lore.kernel.org/all/20220809185229.28417-1-vegard.nossum@oracle.com/

I'll respond to Serge's comment on the v2 thread.


Vegard