{"id":816500,"url":"http://patchwork.ozlabs.org/api/patches/816500/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/1505940337-79069-26-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":"<1505940337-79069-26-git-send-email-keescook@chromium.org>","list_archive_url":null,"date":"2017-09-20T20:45:31","name":"[v3,25/31] fork: Define usercopy region in thread_stack slab caches","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":true,"hash":"6a8e5bf74db87098ec7e72f3145c5e32ae3e433b","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/1505940337-79069-26-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/816500/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816500/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=\"OkJoDSIR\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xyBn11cwvz9s8J\n\tfor ;\n\tThu, 21 Sep 2017 06:54:13 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1752201AbdITUxK (ORCPT );\n\tWed, 20 Sep 2017 16:53:10 -0400","from mail-pg0-f47.google.com ([74.125.83.47]:56983 \"EHLO\n\tmail-pg0-f47.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1752155AbdITUw6 (ORCPT\n\t); Wed, 20 Sep 2017 16:52:58 -0400","by mail-pg0-f47.google.com with SMTP id 7so2332941pgd.13\n\tfor ; Wed, 20 Sep 2017 13:52:58 -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\t133sm10278395pfy.2.2017.09.20.13.52.50\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=x4S+mwfUnv9K1Bnlak1ybFpRjVXdf/L3fqTsDlwg50M=;\n\tb=OkJoDSIRrhJqpumEbdgIZUtTt0WTnFGcLHY08vORZXJnpk/j/KmhcAIKKdkFiFjvAx\n\tioqT+4Da6tO6CJ3TbzmDxLOZBcU8KkJ6+iPOqUO5kf7Re8Tif63lwgN5JGhAFcmAtPth\n\tzpxasFNuBgw549mVSmMShMbbu/nmALPt5E/uw=","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=x4S+mwfUnv9K1Bnlak1ybFpRjVXdf/L3fqTsDlwg50M=;\n\tb=PkqhguB4bFuOyAqqtQzsSu+JD5T7n9gCb6KVovdV/xaxvfp8BUX4sIM4u+Q0timqkH\n\tWyN0uI3XqR4a9ra/RoXhyDVaQxxqzM0YlT5BOGZzD9Rsq9vD5UJhPscd9mh7W5CyJg8Y\n\txdAyltQPf44fyAl+Z3btAVf5+gR0CMyBYds1KZmejimrOBt4Sst6O7C01hq045t01gFs\n\t6dtWJ4RTOr8XcN0OOtZ+f7FWBgH5viLotz8++L5KyaOap/OYTUrYWBbOyrk8p6UWIrjL\n\tFR320wiZzAEw8cKlhg2pBFyVytEbm1aTYyPiS0EiScX7u/UiBjyT2ZSeK5dDBkwodzIb\n\t2ZOQ==","X-Gm-Message-State":"AHPjjUjhK7e1IufRnrKYVwoOczaoP7NmVf0/fgnN64HwNwZiiu+ulhCa\n\tzt/mNbnUz6m2KPCdrDxFQDx7hg==","X-Google-Smtp-Source":"AOwi7QDdvNIGCSvzoIudS00ab5XQGn7EaTU8A7SYRyxuUPb1jMoqLe/+NlgZxYQX2Chlylk5j/9cJw==","X-Received":"by 10.99.125.82 with SMTP id m18mr3464839pgn.347.1505940778162; \n\tWed, 20 Sep 2017 13:52:58 -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 25/31] fork: Define usercopy region in thread_stack slab\n\tcaches","Date":"Wed, 20 Sep 2017 13:45:31 -0700","Message-Id":"<1505940337-79069-26-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\nthread_stack slab caches in which userspace copy operations are allowed.\nSince the entire thread_stack needs to be available to userspace, the\nentire slab contents are whitelisted. Note that the slab-based thread\nstack is only present on systems with THREAD_SIZE < PAGE_SIZE and\n!CONFIG_VMAP_STACK.\n\ncache object allocation:\n kernel/fork.c:\n alloc_thread_stack_node(...):\n return kmem_cache_alloc_node(thread_stack_cache, ...)\n\n dup_task_struct(...):\n ...\n stack = alloc_thread_stack_node(...)\n ...\n tsk->stack = stack;\n\n copy_process(...):\n ...\n dup_task_struct(...)\n\n _do_fork(...):\n ...\n copy_process(...)\n\nThis region is known as the slab cache's usercopy region. Slab caches\ncan now check that each copy operation involving cache-managed memory\nfalls entirely 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---\nI wasn't able to test this, so anyone with a system that can try running\nwith a large PAGE_SIZE and without VMAP_STACK would be appreciated.\n---\n kernel/fork.c | 5 +++--\n 1 file changed, 3 insertions(+), 2 deletions(-)","diff":"diff --git a/kernel/fork.c b/kernel/fork.c\nindex dc1437f8b702..720109dc723a 100644\n--- a/kernel/fork.c\n+++ b/kernel/fork.c\n@@ -278,8 +278,9 @@ static void free_thread_stack(struct task_struct *tsk)\n \n void thread_stack_cache_init(void)\n {\n-\tthread_stack_cache = kmem_cache_create(\"thread_stack\", THREAD_SIZE,\n-\t\t\t\t\t THREAD_SIZE, 0, NULL);\n+\tthread_stack_cache = kmem_cache_create_usercopy(\"thread_stack\",\n+\t\t\t\t\tTHREAD_SIZE, THREAD_SIZE, 0, 0,\n+\t\t\t\t\tTHREAD_SIZE, NULL);\n \tBUG_ON(thread_stack_cache == NULL);\n }\n # endif\n","prefixes":["v3","25/31"]}