{"id":816495,"url":"http://patchwork.ozlabs.org/api/patches/816495/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/1505940337-79069-8-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":"<1505940337-79069-8-git-send-email-keescook@chromium.org>","list_archive_url":null,"date":"2017-09-20T20:45:13","name":"[v3,07/31] ext4: Define usercopy region in ext4_inode_cache slab cache","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":true,"hash":"b345673fa8df2ce34f728b4f8d391eb0fb4c2326","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/1505940337-79069-8-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/816495/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816495/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=\"fGxlDpm3\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xyBjd5WCtz9s83\n\tfor ;\n\tThu, 21 Sep 2017 06:51:17 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751365AbdITUvE (ORCPT );\n\tWed, 20 Sep 2017 16:51:04 -0400","from mail-pf0-f171.google.com ([209.85.192.171]:49619 \"EHLO\n\tmail-pf0-f171.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751839AbdITUqE (ORCPT\n\t); Wed, 20 Sep 2017 16:46:04 -0400","by mail-pf0-f171.google.com with SMTP id l188so2107664pfc.6\n\tfor ; Wed, 20 Sep 2017 13:46:04 -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\tx13sm9309894pgt.16.2017.09.20.13.45.57\n\t(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);\n\tWed, 20 Sep 2017 13:46:00 -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=KHkA7gLl/RRGwjgOyKwgdPKfIPgF/zMmJeyAmhW6qOw=;\n\tb=fGxlDpm3vc2fA/Jp5Y2utCd8pLahnUqHH5urnUO7T33XIdpYnf5EunhApaWtZvFXBZ\n\tPP+lhfzIhN9MC0fnMUrQ9qt/JSve+OY+MsYnT/FJhB5yMZzXWXge3oL7ZWAxcNwbq2qu\n\t3SKnK0rXsWfG0Ow1+CiA5mroMmV9Rrhn3IR/Q=","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=KHkA7gLl/RRGwjgOyKwgdPKfIPgF/zMmJeyAmhW6qOw=;\n\tb=WJcALx75dp1ZlHk4UVbb3A0OCzXuB0pTv62NvV/Ic+qDhzyExwPhvUXLVn1yoPGayh\n\txH6z6wzOIS1VWbN+7Dn9z79pQ7rfHJbPQIFYOJkPT4irAc4P70xhnRmyY9wGk4046Wv6\n\tps4y0G8iKH+lYvu2qpcXGRG6yERs8wo3EpgctXyhVC8Y5jEqQ5utVpg/r8i6yyYe1axW\n\tv0/3urAHgGdbNynHglm/Nw71mj1So6ges1nwfkJkVWyRbe6dPnnNzd3uH5w9FN1fsk4l\n\t9BoUz7Qee0j4S+q+EYHAFJ4BmVHuEXeV5hJMOFsCIq47HbT3Ou1Fp6pFXdrlidwxt49q\n\tSXpA==","X-Gm-Message-State":"AHPjjUindeZPEEg3/iRKKuRq2AtmVtO8KM6jfiUXCCeCFPwq+pVtdLTR\n\tad7GMkB5wMuoqV6Q+Kv6wkMXdw==","X-Google-Smtp-Source":"AOwi7QBE2T8Sem0JxX+dZ9g2uiwe37WR/RLJbYDb7rpoqIGffREbz1I7t/Lcwl6Yfi31ksHmVR+rSg==","X-Received":"by 10.98.211.200 with SMTP id z69mr3328748pfk.112.1505940364314; \n\tWed, 20 Sep 2017 13:46:04 -0700 (PDT)","From":"Kees Cook ","To":"linux-kernel@vger.kernel.org","Cc":"Kees Cook , David Windsor ,\n\t\"Theodore Ts'o\" ,\n\tAndreas Dilger ,\n\tlinux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,\n\tnetdev@vger.kernel.org, linux-mm@kvack.org,\n\tkernel-hardening@lists.openwall.com","Subject":"[PATCH v3 07/31] ext4: Define usercopy region in ext4_inode_cache\n\tslab cache","Date":"Wed, 20 Sep 2017 13:45:13 -0700","Message-Id":"<1505940337-79069-8-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\nThe ext4 symlink pathnames, stored in struct ext4_inode_info.i_data\nand therefore contained in the ext4_inode_cache slab cache, need\nto be copied to/from userspace.\n\ncache object allocation:\n fs/ext4/super.c:\n ext4_alloc_inode(...):\n struct ext4_inode_info *ei;\n ...\n ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);\n ...\n return &ei->vfs_inode;\n\n include/trace/events/ext4.h:\n #define EXT4_I(inode) \\\n (container_of(inode, struct ext4_inode_info, vfs_inode))\n\n fs/ext4/namei.c:\n ext4_symlink(...):\n ...\n inode->i_link = (char *)&EXT4_I(inode)->i_data;\n\nexample usage trace:\n readlink_copy+0x43/0x70\n vfs_readlink+0x62/0x110\n SyS_readlinkat+0x100/0x130\n\n fs/namei.c:\n readlink_copy(..., link):\n ...\n copy_to_user(..., link, len)\n\n (inlined into vfs_readlink)\n generic_readlink(dentry, ...):\n struct inode *inode = d_inode(dentry);\n const char *link = inode->i_link;\n ...\n readlink_copy(..., link);\n\nIn support of usercopy hardening, this patch defines a region in the\next4_inode_cache slab cache in which userspace copy operations are\nallowed.\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, provide usage trace]\nCc: \"Theodore Ts'o\" \nCc: Andreas Dilger \nCc: linux-ext4@vger.kernel.org\nSigned-off-by: Kees Cook \n---\n fs/ext4/super.c | 12 +++++++-----\n 1 file changed, 7 insertions(+), 5 deletions(-)","diff":"diff --git a/fs/ext4/super.c b/fs/ext4/super.c\nindex b104096fce9e..b5d393321b7b 100644\n--- a/fs/ext4/super.c\n+++ b/fs/ext4/super.c\n@@ -1036,11 +1036,13 @@ static void init_once(void *foo)\n \n static int __init init_inodecache(void)\n {\n-\text4_inode_cachep = kmem_cache_create(\"ext4_inode_cache\",\n-\t\t\t\t\t sizeof(struct ext4_inode_info),\n-\t\t\t\t\t 0, (SLAB_RECLAIM_ACCOUNT|\n-\t\t\t\t\t\tSLAB_MEM_SPREAD|SLAB_ACCOUNT),\n-\t\t\t\t\t init_once);\n+\text4_inode_cachep = kmem_cache_create_usercopy(\"ext4_inode_cache\",\n+\t\t\t\tsizeof(struct ext4_inode_info), 0,\n+\t\t\t\t(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|\n+\t\t\t\t\tSLAB_ACCOUNT),\n+\t\t\t\toffsetof(struct ext4_inode_info, i_data),\n+\t\t\t\tsizeof_field(struct ext4_inode_info, i_data),\n+\t\t\t\tinit_once);\n \tif (ext4_inode_cachep == NULL)\n \t\treturn -ENOMEM;\n \treturn 0;\n","prefixes":["v3","07/31"]}