{"id":816505,"url":"http://patchwork.ozlabs.org/api/patches/816505/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/1505940337-79069-25-git-send-email-keescook@chromium.org/","project":{"id":7,"url":"http://patchwork.ozlabs.org/api/projects/7/?format=json","name":"Linux network development","link_name":"netdev","list_id":"netdev.vger.kernel.org","list_email":"netdev@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<1505940337-79069-25-git-send-email-keescook@chromium.org>","list_archive_url":null,"date":"2017-09-20T20:45:30","name":"[v3,24/31] fork: Define usercopy region in mm_struct slab caches","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":true,"hash":"c9bf56634def5d792d8a3cca07a19cefa785a0c6","submitter":{"id":10641,"url":"http://patchwork.ozlabs.org/api/people/10641/?format=json","name":"Kees Cook","email":"keescook@chromium.org"},"delegate":{"id":34,"url":"http://patchwork.ozlabs.org/api/users/34/?format=json","username":"davem","first_name":"David","last_name":"Miller","email":"davem@davemloft.net"},"mbox":"http://patchwork.ozlabs.org/project/netdev/patch/1505940337-79069-25-git-send-email-keescook@chromium.org/mbox/","series":[{"id":4231,"url":"http://patchwork.ozlabs.org/api/series/4231/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/list/?series=4231","date":"2017-09-20T20:45:22","name":"Hardened usercopy whitelisting","version":3,"mbox":"http://patchwork.ozlabs.org/series/4231/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/816505/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816505/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (1024-bit key;\n\tunprotected) header.d=chromium.org header.i=@chromium.org\n\theader.b=\"mQUXuIpb\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xyBs00whtz9s8J\n\tfor ;\n\tThu, 21 Sep 2017 06:57:40 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1752136AbdITU5Q (ORCPT );\n\tWed, 20 Sep 2017 16:57:16 -0400","from mail-pg0-f43.google.com ([74.125.83.43]:55624 \"EHLO\n\tmail-pg0-f43.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751946AbdITUw5 (ORCPT\n\t); Wed, 20 Sep 2017 16:52:57 -0400","by mail-pg0-f43.google.com with SMTP id b11so2329447pgn.12\n\tfor ; Wed, 20 Sep 2017 13:52:57 -0700 (PDT)","from www.outflux.net\n\t(173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133])\n\tby smtp.gmail.com with ESMTPSA id\n\tv126sm8020329pfv.113.2017.09.20.13.52.49\n\t(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);\n\tWed, 20 Sep 2017 13:52:52 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=chromium.org; s=google;\n\th=from:to:cc:subject:date:message-id:in-reply-to:references;\n\tbh=TkrW+cp+dMAWhCp1Dv3tVOWEK31GdBbqko5g+n8xJ0o=;\n\tb=mQUXuIpbOEJdfdaWpR5DNntxbkXu5r1EgrXyktr5GJrTNqoG2/pzRW50BNZRlj4/GZ\n\t1xRnTfH+zMBJoH6qAy0OjKUdDCU19mCT4Sd59c8e7GkQkxuCktAwhsbd/8RyZYXzL1EE\n\tSP+VO9sPa5X8HVPHWAzZoxpO9zvZJBhrQWdYg=","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to\n\t:references;\n\tbh=TkrW+cp+dMAWhCp1Dv3tVOWEK31GdBbqko5g+n8xJ0o=;\n\tb=VLKlClJTlisCBXazTmJ2VjK9/hKcP1ig0+k11IWFsX6fPZTrdoir1QpFEUoPhDRCzA\n\tjrx3o9FPAoNKYICHyz4NNKp4H4ctJoYffEKP5YNyWnwqGMvGDoogv2RT7m6J0si8be15\n\tG2fIX6AlBGVa4C/4YQLXU9TetEf92Zrk8qKtqR5kEGvOSPtcYaElT7x27KwT3drirS0F\n\tLfCUc10J8/TEEklYEAw2qZPubxi4hAAhKhsjmHiclelHB5R2RmxPJk3zFqSZ6gCU8ahI\n\tl03LiGMU6ROydyMZy5Am1U/9XiF66JTsN3hzhYl0XdygBUUdlaq4gtjX9H9hzJ6E8uoq\n\tGKYw==","X-Gm-Message-State":"AHPjjUj4HkhkUebHA6Wt9L9Tb0PszNrH5FfzQqwnjCVJpkzmR4b29G/t\n\tJcxQFfyerwPmyXVMcHRzDWoReg==","X-Google-Smtp-Source":"AOwi7QDSKRuTwy2OkBnxeHCBZvZQE3MujyfMLV3/el7sf5sCBMlQwnm42XUdWC/iPZY3wIm5ST5t9g==","X-Received":"by 10.84.129.193 with SMTP id b59mr3366400plb.200.1505940776799; \n\tWed, 20 Sep 2017 13:52:56 -0700 (PDT)","From":"Kees Cook ","To":"linux-kernel@vger.kernel.org","Cc":"Kees Cook , David Windsor ,\n\tIngo Molnar ,\n\tAndrew Morton ,\n\tThomas Gleixner , Andy Lutomirski ,\n\tlinux-fsdevel@vger.kernel.org, netdev@vger.kernel.org,\n\tlinux-mm@kvack.org, kernel-hardening@lists.openwall.com","Subject":"[PATCH v3 24/31] fork: Define usercopy region in mm_struct slab\n\tcaches","Date":"Wed, 20 Sep 2017 13:45:30 -0700","Message-Id":"<1505940337-79069-25-git-send-email-keescook@chromium.org>","X-Mailer":"git-send-email 2.7.4","In-Reply-To":"<1505940337-79069-1-git-send-email-keescook@chromium.org>","References":"<1505940337-79069-1-git-send-email-keescook@chromium.org>","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"},"content":"From: David Windsor \n\nIn support of usercopy hardening, this patch defines a region in the\nmm_struct slab caches in which userspace copy operations are allowed.\nOnly the auxv field is copied to userspace.\n\ncache object allocation:\n kernel/fork.c:\n #define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))\n\n dup_mm():\n ...\n mm = allocate_mm();\n\n copy_mm(...):\n ...\n dup_mm();\n\n copy_process(...):\n ...\n copy_mm(...)\n\n _do_fork(...):\n ...\n copy_process(...)\n\nexample usage trace:\n\n fs/binfmt_elf.c:\n create_elf_tables(...):\n ...\n elf_info = (elf_addr_t *)current->mm->saved_auxv;\n ...\n copy_to_user(..., elf_info, ei_index * sizeof(elf_addr_t))\n\n load_elf_binary(...):\n ...\n create_elf_tables(...);\n\nThis region is known as the slab cache's usercopy region. Slab caches can\nnow check that each copy operation involving cache-managed memory falls\nentirely within the slab's usercopy region.\n\nThis patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY\nwhitelisting code in the last public patch of grsecurity/PaX based on my\nunderstanding of the code. Changes or omissions from the original code are\nmine and don't reflect the original grsecurity/PaX code.\n\nSigned-off-by: David Windsor \n[kees: adjust commit log, split patch, provide usage trace]\nCc: Ingo Molnar \nCc: Andrew Morton \nCc: Thomas Gleixner \nCc: Andy Lutomirski \nSigned-off-by: Kees Cook \nAcked-by: Rik van Riel \n---\n kernel/fork.c | 4 +++-\n 1 file changed, 3 insertions(+), 1 deletion(-)","diff":"diff --git a/kernel/fork.c b/kernel/fork.c\nindex 10646182440f..dc1437f8b702 100644\n--- a/kernel/fork.c\n+++ b/kernel/fork.c\n@@ -2207,9 +2207,11 @@ void __init proc_caches_init(void)\n \t * maximum number of CPU's we can ever have. The cpumask_allocation\n \t * is at the end of the structure, exactly for that reason.\n \t */\n-\tmm_cachep = kmem_cache_create(\"mm_struct\",\n+\tmm_cachep = kmem_cache_create_usercopy(\"mm_struct\",\n \t\t\tsizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,\n \t\t\tSLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK|SLAB_ACCOUNT,\n+\t\t\toffsetof(struct mm_struct, saved_auxv),\n+\t\t\tsizeof_field(struct mm_struct, saved_auxv),\n \t\t\tNULL);\n \tvm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC|SLAB_ACCOUNT);\n \tmmap_init();\n","prefixes":["v3","24/31"]}