{"id":806788,"url":"http://patchwork.ozlabs.org/api/1.0/patches/806788/?format=json","project":{"id":8,"url":"http://patchwork.ozlabs.org/api/1.0/projects/8/?format=json","name":"Linux ext4 filesystem development","link_name":"linux-ext4","list_id":"linux-ext4.vger.kernel.org","list_email":"linux-ext4@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<1503956111-36652-8-git-send-email-keescook@chromium.org>","date":"2017-08-28T21:34:48","name":"[v2,07/30] ext4: Define usercopy region in ext4_inode_cache slab cache","commit_ref":null,"pull_url":null,"state":"new","archived":true,"hash":"b345673fa8df2ce34f728b4f8d391eb0fb4c2326","submitter":{"id":10641,"url":"http://patchwork.ozlabs.org/api/1.0/people/10641/?format=json","name":"Kees Cook","email":"keescook@chromium.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-ext4/patch/1503956111-36652-8-git-send-email-keescook@chromium.org/mbox/","series":[{"id":267,"url":"http://patchwork.ozlabs.org/api/1.0/series/267/?format=json","date":"2017-08-28T21:34:48","name":null,"version":2,"mbox":"http://patchwork.ozlabs.org/series/267/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/806788/checks/","tags":{},"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=linux-ext4-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=\"f4+KzIIL\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xh55P4m6Zz9t2R\n\tfor ;\n\tTue, 29 Aug 2017 07:49:29 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751582AbdH1Vf1 (ORCPT );\n\tMon, 28 Aug 2017 17:35:27 -0400","from mail-pg0-f53.google.com ([74.125.83.53]:37241 \"EHLO\n\tmail-pg0-f53.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751499AbdH1VfW (ORCPT\n\t); Mon, 28 Aug 2017 17:35:22 -0400","by mail-pg0-f53.google.com with SMTP id 83so4928364pgb.4\n\tfor ;\n\tMon, 28 Aug 2017 14:35:22 -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\td67sm2196059pfg.27.2017.08.28.14.35.17\n\t(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);\n\tMon, 28 Aug 2017 14:35:19 -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=GwIrOyNMM43PFCitRpZ60qqOK3YH+Fds+Kgy/vS6VOY=;\n\tb=f4+KzIILDPsYJ5MFyqO/BQ3bEzybNX5HA7P5QGReuBJqlZiVAFrrhOjWpxeY5kSMbS\n\tQCjHkDRZ8+fZGvAwv5zg8L7AAboQRTGAxpEUC1VF2lK6fix6Ml0xeDJ/AHjLB7+IYBea\n\tt0q7oAqDpGcBefqsD46dsJkyW4j6IKt8UAg6I=","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=GwIrOyNMM43PFCitRpZ60qqOK3YH+Fds+Kgy/vS6VOY=;\n\tb=q16GZv5pBMZ+0MZ2dgY7aBmh1W4lnzP9vdGcelRyHPBaNCMupsDce1aQasttt5aS34\n\tQRhLoYnrHSg0zdSnoe7Cnq+0Wf/lCjQj8wp3yKKJ4OTOohAZ7tovn00GF5W3C2TtBBZI\n\tFJ66Zj2W3WnTdOnFtFYKaUM+1NVSOtKXuTTuGQqtIMSlAg3laJvnseUloKlgEoPJC/p/\n\tu7I300bB0D40IeXkZ7PfvhHLmYbQd9kROCakd2w4TC/BD+1JjXdhdaL6ePB9ZmdR/REs\n\tZkCEiUS18gwMWzfpgE9/2/1mEwEBmEQaHwxSF6KPPBxSPoeiaU/gtnAekAs0dTgWPSsZ\n\tmGGg==","X-Gm-Message-State":"AHYfb5hfRrHHIAZUxt3zqjpXFY64SsRKxGwgrXr4Pj1x6ujUHHEr3XX6\n\t+U7Fl+Jl1r8A5H/B","X-Received":"by 10.84.210.228 with SMTP id a91mr2362526pli.66.1503956122031; \n\tMon, 28 Aug 2017 14:35:22 -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-mm@kvack.org,\n\tkernel-hardening@lists.openwall.com","Subject":"[PATCH v2 07/30] ext4: Define usercopy region in ext4_inode_cache\n\tslab cache","Date":"Mon, 28 Aug 2017 14:34:48 -0700","Message-Id":"<1503956111-36652-8-git-send-email-keescook@chromium.org>","X-Mailer":"git-send-email 2.7.4","In-Reply-To":"<1503956111-36652-1-git-send-email-keescook@chromium.org>","References":"<1503956111-36652-1-git-send-email-keescook@chromium.org>","Sender":"linux-ext4-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-ext4@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 0886fe82e9c4..79c3b1b11364 100644\n--- a/fs/ext4/super.c\n+++ b/fs/ext4/super.c\n@@ -1038,11 +1038,13 @@ 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":["v2","07/30"]}