From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1150044-1522620387-2-6337560715515440972 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, T_TVD_MIME_EPI 0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='net', MailFrom='org' X-Spam-charsets: from='UTF-8', plain='utf-8' X-Attached: signature.asc X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1522620386; b=DvEYuMj+pGp9lZGmq+C8KwoOrXVEIOShW16lH5U4FGXyWc0BS1 laj6mVBBmd+Ne34uDoN8uhcC8Itr78OHjwOyGeNee4MV9/FuuZUO3lYWc6eOOi8o PX47B1xWvGKytp1Ua/KKi9ryksnHpnfw3yym0NBhzkzriBjFL30EmV7bMhOyWuWn HgJ0yFsBvePoSgIs2/0+yxu+09bOehsNKhrKGcbIZ8zvXKLgUvDxsQt5E/pnCuJa 5TvK5ESrMVoNK4TbuqF/oquwOfWzjee4t1iCzmxQE0lU99p4LkWgVgJtSRHKUx0x RZYsMTnEQpttKJDbyHZR0yZPIw5Tpdg3dU/w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:subject:to:cc:references:message-id :date:mime-version:in-reply-to:content-type:sender:list-id; s= fm2; t=1522620386; bh=NWiui1P0zMsPun3AP06sqz7vUp+8OuPjLMTvWNQ7W8 A=; b=kOrkbg4lPlyKtyfB5dGLp4XyRy+6xUlHTaNLUtejl6ZimQeNbBuTv8/FaL aICpx+NM5pBYDtvL4jUrI2avnSMypeB4jiwxxttF1o8K/Y6TUcJDQaHaokYbzKzw Y/iRQpMHyDv1aFEzcqIFskuT7D6H8sFfcgb99QKCAPSMzt2YzsRprF9z+Zfo7Ed5 7bLOjncHK6kwm+xguOcrOgfFEjfPJS/nxgQ3Vs7KYETZ8QRQ15EWDMbPceWGTbX3 PWVIFYdmb5gGt/4wLSZJOuFL8kVXQhMk7ylFD7jN4N3I0Ig8fH5YbqukrzqBD3pO vfoLoFISr18rUM+b1p8IuOddMgpQ== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=digikod.net; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=digikod.net header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=digikod.net; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=digikod.net header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfBro+JwYatOEsKIbpPV1adxC5/d9JptLOJ5BxiPGpDbWEdYcKw+vaov/klcl1qRZ9ixhUUKJw+2hvFy1009QNQivhvg+HpQaCxMwnk2gmYbiDVVyO0RY /FNQnKI3jgmU6Axn7GyNkQMe/OdrL5DbbjHiTMTwjssq7+B/Mii8jzXzzNIrleVPrXwsdzYGYT7ibL0pxGMKzUvheoalD/55RQR7+SHWS2D/7as50Q5MorzD X-CM-Analysis: v=2.3 cv=Tq3Iegfh c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=Kd1tUaAdevIA:10 a=13zjGPudsaEWiJwPRgMA:9 a=edGIuiaXAAAA:8 a=NEAV23lmAAAA:8 a=u0g3DNdEotHYdBcwH1sA:9 a=EeRac8_LPce7KGSK:21 a=v1Xy5OI-KIA9XODu:21 a=QEXdDO2ut3YA:10 a=Hx2OsaOEbP_rrlqbww4A:9 a=ONNS8QRKHyMA:10 a=VwQbUJbxAAAA:8 a=fUSZZkATYxXnQMecnGkA:9 a=x8gzFH9gYPwA:10 a=4kyDAASA-Eebq_PzFVE6:22 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926AbeDAWGZ (ORCPT ); Sun, 1 Apr 2018 18:06:25 -0400 Received: from smtp-sh2.infomaniak.ch ([128.65.195.6]:50572 "EHLO smtp-sh2.infomaniak.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753915AbeDAWGW (ORCPT ); Sun, 1 Apr 2018 18:06:22 -0400 From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= Subject: [PATCH bpf-next v8 00/11] Landlock LSM: Toward unprivileged sandboxing To: Andy Lutomirski Cc: Tycho Andersen , LKML , Alexei Starovoitov , Arnaldo Carvalho de Melo , Casey Schaufler , Daniel Borkmann , David Drysdale , "David S . Miller" , "Eric W . Biederman" , James Morris , Jann Horn , Jonathan Corbet , Michael Kerrisk , Kees Cook , Paul Moore , Sargun Dhillon , "Serge E . Hallyn" , Shuah Khan , Tejun Heo , Thomas Graf , Will Drewry , Kernel Hardening , Linux API , LSM List , Network Development References: <20180227004121.3633-1-mic@digikod.net> <2e06621c-08e9-dc12-9b6e-9c09d5d8f458@digikod.net> <20180306224636.wf5z3kujtc7r5qyh@cisco> <7082be04-d6af-b853-4bb7-f331836662e2@digikod.net> Openpgp: preference=signencrypt Autocrypt: addr=mic@digikod.net; keydata= xsFNBFNUOTgBEAC5HCwtCH/iikbZRDkXUSZa078Fz8H/21oNdzi13NM0ZdeR9KVq28ZCBAud law2P+HhaPFuZLqzRiy+iNOumPgrUyNphLhxWby/JgD7hvhYs5HJgdX0VTwzGqprmAeDKbnS G0Q2zxmnkb1/ENRTfrOIBm5LwyRhWIw5hg+HKh88g6qztDHdVSGqgWGLhj7RqDgHCgC4kAve /tWwfnpmMMndi5V+wg5EanyiffjAq6GHwzWbal+u3lkV8zNo15VZ+6mOY3X6dfYFVeX8hAP4 u6OxzK4dQhDMVnJux5jum8RXtkSASiQpvx80npFbToIMgziWoWPV+Ag3Ti9JsactNzygozjL G0j8nc4dtfdkFoflEqtFIz2ZVWlmvcjbxTbvFpK2TwbVSiXe3Iyn4FIatk8tPsyY+mwKLzsc RNXaOXXB3kza0JmmnOyLCZuCTkds8FHvEG3nMIvyzXiobFM5F2b5Xo5x0fSo2ycIXXWgNJFn X1QXiPEM+emIRH0q2mHNAdvDki/Ns+qmkI4MQjWNGLGzlzb2GJBb5jXmkxEhk0/hUXVK3WYu /jGRQAbyX3XASArcw4RNFWd6fwzsX4Ras52BwI2qZaVAh4OclArEoSh5lGweizpN+1K8SnxG zVmvUDS8MfwlO97Kge4jzD0nRFOVE/z2DOLp6ZOcdRTxmTZNEwARAQABzSJNaWNrYcOrbCBT YWxhw7xuIDxtaWNAZGlnaWtvZC5uZXQ+wsF9BBMBCgAnBQJTVDk4AhsDBQkLRzUABQsJCAcD BRUKCQgLBRYDAgEAAh4BAheAAAoJECkv1ZR9XFaW/64P/3wPay/u16aRGeRgUl7ZZ8aZ50WH kCZHmX/aemxBk4lKNjbghzQFcuRkLODN0HXHZqqObLo77BKrSiVwlPSTNguXs9R6IaRfITvP 6k1ka/1I5ItczhHq0Ewf0Qs9SUphIGa71aE0zoWC4AWMz/avx/tvPdI4HoQop4K3DCJU5BXS NYDVOc8Ug9Zq+C1dM3PnLbL1BR1/K3D+fqAetQ9Aq/KP1NnsfSYQvkMoHIJ/6s0p3cUTkWJ3 0TjkJliErYdn+V3Uj049XPe1KN04jldZ5MJDEQv5G3o4zEGcMpziYxw75t6SJ+/lzeJyzJjy uYYzg8fqxJ8x9CYVrG1s8xcXu9TqPzFcHszfl9N01gOaT5UbJrjI8d2b2SG7SR9Wzn9FWNdy Uc/r/enMcnRkiMgadt6qSG+Z0UMwxPt/DTOkv5ISxyY8IzDJDCZ5HrBd9hTmTSztS+UUC2r1 5ijaOSCTWtGgJz/86ERDiUULZmhmQ1C9On46ilAgKEq4Eg3fXy6+kMaZXT3RTDrCtVrD4U58 11KD1mR4y8WwW5LJvKikqspaqrEVC4AyAbLwEsdjVmEVkdFqm6qW4YbaK+g/Wkr0jxuJ0bVn PTABQxmDBVUxsE6qDy6+s8ZWoPfwI1FK2TZwoIH0OQiffSXx6mdEO5X4O4Pj7f8pz723xCxV 1hqz/rrZzsBNBFNUOVIBCAC8V01O2A6U2REVue2XTC358B7ZYr8omGeyaEffDmHVA7KOqsJd 3rTNsUkxJtHGbFhCOeOBMZpgZbxhvrd+JkfHrA4A3QYf1z040oTW6v47ns2CrpGI9HZKlnGL RKGbQ+NkKWnhrIBmgk7EjbNVCa0zlzKdFkbaeOB/K8IMux6gky1KbM2iq/KjkNimGSoRKtnL o/rc8mmOGb7Y5I0nBWANE3lWC1oQXbnT4tsYpTeruA95STcwYYaThGMjIXHnvlhtt/uHdNiZ dZ2jxkmWDDQCo8JY1Md47CZzgX0F8F3Yyxd2rvPQzPqCmdsneUNFD9Hf3nSwxXe25Rob3a7M wQbLABEBAAHCwWUEGAEKAA8CGwwFAlNUOVgFCQHhM4YACgkQKS/VlH1cVpYyhg//Qn0PgNOt kd7gL5ZfvJdlpaNM61KhDd1s1fM8rpiacADy/rMGu1GoxmWotw2psfCqExKQoHoiMOy7FJ2v X0w5n5BdsMa9AzS+OpCFjNmNJqsYlfKuOSGLwz7rnmfRupmMnXll4GR4Qk4KhDdR1jK+NOnt SV3df6gpySsq12icpLXSotzg/Ql0a2RDU0lxGbAbXW9kmU5tD4/xxqb2SgG8ffrW+Grewc3c Hn9Kip/l7b2N2NNHnfMDuzz7Okn7qZdq7rBiJJiDseI1gt4J7bcApgB8/B7sRTfEACQgelI7 NM5TpXnUCjYVA/3cahQ77eNFYVwDRrW9IDFgIPLlzc+KAoEA++6Bk5gjWzIz6ktFTgcv51Jp uDKHTLGK7MEeMas0el7UdqItoTg3Y7WRxhtyoRnTTVyebq78HLt7CVyov5imxdPaqSawnI8R dfmZMCvZCz3FZzv64lekh/XR6jI1gwarmL+8SB3S/B7TmpyKsuAA+sElPuSJ7txNG9w8z4HV zdS9dGwDr63rFFYZOMeSgc2yeAxvEbreat/oKrzhdIRgOQbDlqT8KfehyxB075GGzb3cQUH3 ffcWovjiD4QqAIcWuCnCgImlZvYvKREjitH8iWhVOwUzCg8axzTG9dnd12ip3H5J+xczSrPQ V9NIH/8N/96armypjCg04LiWxnzCwWUEGAEKAA8CGwwFAlUaObIFCQOnM+AACgkQKS/VlH1c Vpa+FA/6AtC2lutrmBHZuT2Uw+Hh0/ghuFq3hGaRsaHVyHnHGPnDVJJH4/1ugnvC4nxKJp+O SNZ3ntGIgOgGlMZ4d2MzDXVTh/wqbefveldklOcBwTDr29EieWYyoFnp/mo0D5JhyWRqtP5F xlZWkAJa6qHQUj12+8C+m9LCprOzm+iZyKyGgCzWRl1H840YLsHgL/XBnzhXbTAaJFfgCGAe 2cbcDdEo+gs8Kgsoli7q9RFBjzCd0hTojvbf7RKU8dSoPGeL59We4UbjWW2EwWdTD0ASIO6g VOWbZ/VxLdAZ2kYmNhRKB12vXlFoTlE4kiyBz9nka86e17tx53+Fpo5k/TjYLmiXMCQKMvl2 jGuO1UWBkqa3xt9JEtanzWzAJv/MJFrvgd0efAPGJmlnticzcgcGfkbWBW2jLTYm+FLqyhXx 6e9jjFyiEy+wxnV6TpLpmRGY87BHx7OabNLqz0jFcftCzGkwJlyOVo5ieaaw9t22aboFHz4Y P9pHTxEvBPI6HSVCxIDMKepNuh2C7uTP/lOzfMz5PjtGjA8qeozeheZRyVgmxQ8qUNZznX8/ 3hJz19ymMRy4Cryfsd+Zca61BoqRgcM/XAsViNSEMIIDI7KC2YixrhoplF3K9GtEM3Ul/IBF z4c/TqGMID/WTBfJKb30XGam3zAnp795CKk1KVfKAXzCwWUEGAEKAA8CGwwFAlb6/8sFCQWH +fkACgkQKS/VlH1cVpaD9hAAtAyrMBQL3mG6g38K0eRlcbC4oy0KFi7xFkwKVSw5K8yMm8bu T4azHOxCiJR1zNmhHD446hdjK3qiwT46hl5PILTkCjFSPW474YrRWMCC7hYbeYhAA5sSRNuP DduqFKy/SbWOtTnHaEUxYVeY96eErIgRoTXOjpjdNMnHbL3h/Zv01bFGRsxrc6/Hgjuupp8Q JO90p3TfARgVbVbrA4wkcCHexI9FqMmuEDrPBAwuqKrdBI2N2byuloSJRXQ4p/5s3gfzKKHw 4+M0yN/QCR+2TI3rj+bHVcWEHi5unaCHsFwxFwFtZB4yA0TJ8X6ab6h7aDzkgKxLyFIx3ZNS y6SGW+wH+Jzt3b2gbaYO+SeGdYHpQvdsldFIFFGTEaI2m+Fj55PbB1qArEWlGMRKTw9HgD2G iYZ3g6kwGox23SKdv0Rvtbq+WoLP4aL/4CHTj4EA/k/kI9DCq93kv0XWjJvTjLCo1nui4nzG pX8LtOAirwzVd96Wklbmxkx50LZYpXK0uK0+SyBF0uQnLqPpwgH1r8GCX5Ri9CAUIZo5sTZQ Z3WWDgDqHKVfTF1XrupvTfu50h3zDc0ze4zQJ9sYQ5jGepSZkQ4M1uTMkep072WJrj+lDUax ha6PX5yPZ2mVMuP6RNX9HwXPykqCzTahbnZR4atbuNumw6xfHIOWPFuL7cLCwWUEGAEKAA8C GwwFAljavs4FCQds/oEACgkQKS/VlH1cVpYMlQ//ZYTCxnTSiCuB+2v6sWRMvr7nHC+jzeM6 tXocYFZdbuXJynRbehASZHiKt3Eg2z6XgDm/AGEF4XECKakiNEgleJWZwQIGefuUZbRmH+6A BVJ49Q03baT88zcp5s8Ci2mum7krkZ8fr6T/DpZB+FWQvfzFNWJ/mTttEInQgmkTkZgxArqh 36ZsNK8BJWVo6caYGnDs6kqz19HurNYzmr2a7Xz/sXkCFne57nnWZ/A5k2PZQAS2JZioqz+9 wnPxCOKLOjEw/kd2dKqyY7e42DDVH4J85uYK4q+jhZ2Ou5jBBVjrZvUPzCbJgSg694mx04zw LkpOBhmQWShXo/GJR7S4dykTwMude1eBJVWTq5epaRbD7AbO8nSkmDvAlHL+ee2zPsC0OEqt 8gzLNpU37BI5T9mXoqkFwaabkXmRw40vVZwUEtINOyCs9U0JxUQd9KsV+nEBYtOhwItJEORP vLjSv934huHhrs1duExKK6GDdNCcOkfaJtV4BG+un/Sp8eZhQxlswkJ9DuWxaMZWauTPT8Ok 2wMFP50c6YOyMxeIVpDLC5zYGjow/1+x/RkaME3XUkEQoUtmYbovmVySjl0DFIlnPf1k68ol PbtcpwExD3XOXbp/xU7MAoeeiU52167JzfpgudvFYDMKPKevxbpQ3krOYEoj7LQMGLj9a8YL E1DCwWUEGAEKAA8CGwwFAlq+mvkFCQlOOCcACgkQKS/VlH1cVpaJXg/+P3T2eJOJsHXg6A+W 5Ipqwr3e3mi1PwF+B+L6nllcx0KOG4RuuEbAQaNCrLU4T+3CbOm5hr1AK4I+LHXb+tIQf9i+ RFuxARWJgVFWObaOj3gIAPRI6ZH8mHE5fHw14JFrMYtjBA0MC1ipKhvDNWzwgOXntta46epB aJyc66mjFOB/xuBVbI5DdMix/paJB9hxfaQ3svhPrm25P6nqOtL3iSqMV0pyfWCBzoex2L2A aBcY6D3ooa6KNMTM9FVcvV1spRRNCYxa2Ls8sPou1WD+zNtfe+cag8N7J+i0NphbcYZ7jHgy IVV8IK2f0vjkMfpZrQzkFKghUv7KZio2y79+nqK1gc88czsIFB0qYbTPn5nNTwZW3wmRWpiv Ivqj6OYvSWDn0Pc0ldGTy/9TK+Azu7p7+OkG9BZMacd7ovXKKCJUSVSiSAcDdK/IslgBHSOZ GSdPtkvOI2oUzToZm1dtfoNCpozcblksL5Eit2LlSIAhDuFvmY3tNPnSV+ei37QojHHt2CWL N8DVEAxQtBqDVk4Cg12cQg/Zo+/hYfsmJSpGkb6qoE2qL26MUyILOdYD+ztR7P3XEnwK/W8C 00XQg7XfdfyOdb/BNjoyPO5+cOArcN+wl839TELr6qsKbGMueebw4l778RIVBJlYfzQh4n77 RjVFnCHFbtPhnyvGdQQ= Message-ID: <0f355079-7ee2-c06a-2d47-a7a2fa6d98fe@digikod.net> Date: Mon, 2 Apr 2018 00:04:36 +0200 User-Agent: MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="7ETR9AiFPQ2Uq7fMG9rud0cfSy2GGUryC" X-Antivirus-Code: 0x100000 Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --7ETR9AiFPQ2Uq7fMG9rud0cfSy2GGUryC Content-Type: multipart/mixed; boundary="F0X3aGkiRSyJCWu2SB4Vbzc5KAEyYJSt8"; protected-headers="v1" From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= To: Andy Lutomirski Cc: Tycho Andersen , LKML , Alexei Starovoitov , Arnaldo Carvalho de Melo , Casey Schaufler , Daniel Borkmann , David Drysdale , "David S . Miller" , "Eric W . Biederman" , James Morris , Jann Horn , Jonathan Corbet , Michael Kerrisk , Kees Cook , Paul Moore , Sargun Dhillon , "Serge E . Hallyn" , Shuah Khan , Tejun Heo , Thomas Graf , Will Drewry , Kernel Hardening , Linux API , LSM List , Network Development Message-ID: <0f355079-7ee2-c06a-2d47-a7a2fa6d98fe@digikod.net> Subject: [PATCH bpf-next v8 00/11] Landlock LSM: Toward unprivileged sandboxing References: <20180227004121.3633-1-mic@digikod.net> <2e06621c-08e9-dc12-9b6e-9c09d5d8f458@digikod.net> <20180306224636.wf5z3kujtc7r5qyh@cisco> <7082be04-d6af-b853-4bb7-f331836662e2@digikod.net> In-Reply-To: --F0X3aGkiRSyJCWu2SB4Vbzc5KAEyYJSt8 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 03/09/2018 12:53 AM, Andy Lutomirski wrote: > On Thu, Mar 8, 2018 at 11:51 PM, Micka=C3=ABl Sala=C3=BCn wrote: >> >> On 07/03/2018 02:21, Andy Lutomirski wrote: >>> On Tue, Mar 6, 2018 at 11:06 PM, Micka=C3=ABl Sala=C3=BCn wrote: >>>> >>>> On 06/03/2018 23:46, Tycho Andersen wrote: >>>>> On Tue, Mar 06, 2018 at 10:33:17PM +0000, Andy Lutomirski wrote: >>>>>>>> Suppose I'm writing a container manager. I want to run "mount" = in the >>>>>>>> container, but I don't want to allow moun() in general and I wan= t to >>>>>>>> emulate certain mount() actions. I can write a filter that catc= hes >>>>>>>> mount using seccomp and calls out to the container manager for h= elp. >>>>>>>> This isn't theoretical -- Tycho wants *exactly* this use case to= be >>>>>>>> supported. >>>>>>> >>>>>>> Well, I think this use case should be handled with something like= >>>>>>> LD_PRELOAD and a helper library. FYI, I did something like this: >>>>>>> https://github.com/stemjail/stemshim >>>>>> >>>>>> I doubt that will work for containers. Containers that use user >>>>>> namespaces and, for example, setuid programs aren't going to honor= >>>>>> LD_PRELOAD. >>>>> >>>>> Or anything that calls syscalls directly, like go programs. >>>> >>>> That's why the vDSO-like approach. Enforcing an access control is no= t >>>> the issue here, patching a buggy userland (without patching its code= ) is >>>> the issue isn't it? >>>> >>>> As far as I remember, the main problem is to handle file descriptors= >>>> while "emulating" the kernel behavior. This can be done with a "shim= " >>>> code mapped in every processes. Chrome used something like this (in = a >>>> previous sandbox mechanism) as a kind of emulation (with the current= >>>> seccomp-bpf ). I think it should be doable to replace the (userland)= >>>> emulation code with an IPC wrapper receiving file descriptors throug= h >>>> UNIX socket. >>>> >>> >>> Can you explain exactly what you mean by "vDSO-like"? >>> >>> When a 64-bit program does a syscall, it just executes the SYSCALL >>> instruction. The vDSO isn't involved at all. 32-bit programs usuall= y >>> go through the vDSO, but not always. >>> >>> It could be possible to force-load a DSO into an entire container and= >>> rig up seccomp to intercept all SYSCALLs not originating from the DSO= >>> such that they merely redirect control to the DSO, but that seems >>> quite messy. >> >> vDSO is a code mapped for all processes. As you said, these processes >> may use it or not. What I was thinking about is to use the same concep= t, >> i.e. map a "shim" code into each processes pertaining to a particular >> hierarchy (the same way seccomp filters are inherited across processes= ). >> With a seccomp filter matching some syscall (e.g. mount, open), it is >> possible to jump back to the shim code thanks to SECCOMP_RET_TRAP. Thi= s >> shim code should then be able to emulate/patch what is needed, even >> faking a file opening by receiving a file descriptor through a UNIX >> socket. As did the Chrome sandbox, the seccomp filter may look at the >> calling address to allow the shim code to call syscalls without being >> catched, if needed. However, relying on SIGSYS may not fit with >> arbitrary code. Using a new SECCOMP_RET_EMULATE (?) may be used to jum= p >> to a specific process address, to emulate the syscall in an easier way= >> than only relying on a {c,e}BPF program. >> >=20 > This could indeed be done, but I think that Tycho's approach is much > cleaner and probably faster. >=20 I like it too but how does this handle file descriptors? --F0X3aGkiRSyJCWu2SB4Vbzc5KAEyYJSt8-- --7ETR9AiFPQ2Uq7fMG9rud0cfSy2GGUryC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEUysCyY8er9Axt7hqIt7+33O9apUFAlrBV3oACgkQIt7+33O9 apW/BwgAqUk8+THqVZY7dPxk0Y4kTe3qwu9scB3Kx57Cx/v+cMpbmeySP9XJthTo YDTcKLyeCiHJofBXFqxDq1AI0rtPJNgPRmhS8I038dnQf3qPr/kLdVd0uVJ79ugv H7GeP46pPrPXTw3/JZlJVm9c9TtsCYLFxVNt+rwNgNtm9y5vhN7D8WEKthS8dwb1 kfc2HdNTGnlXGtz4ZKOhUg5YceNmgcL6kvX2GswUZ2D7YRZBhMDfoD/JvGqTli8q dQUGma4Dr9bbzzJhkdNG7uSJTHM2G0EIeWSGOZ+6Zmm5210JPJ1OUdDcNrApuInp qrmx31lKVQgLKbsqitN79O2Bsos9AA== =eLbl -----END PGP SIGNATURE----- --7ETR9AiFPQ2Uq7fMG9rud0cfSy2GGUryC--