From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752863AbdFSXhO (ORCPT ); Mon, 19 Jun 2017 19:37:14 -0400 Received: from mail-pf0-f174.google.com ([209.85.192.174]:32840 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbdFSXhM (ORCPT ); Mon, 19 Jun 2017 19:37:12 -0400 From: Kees Cook To: kernel-hardening@lists.openwall.com Cc: Kees Cook , David Windsor , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 13/23] ufs: define usercopy region in ufs_inode_cache slab cache Date: Mon, 19 Jun 2017 16:36:27 -0700 Message-Id: <1497915397-93805-14-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497915397-93805-1-git-send-email-keescook@chromium.org> References: <1497915397-93805-1-git-send-email-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Windsor The ufs symlink pathnames, stored in struct ufs_inode_info.i_u1.i_symlink and therefore contained in the ufs_inode_cache slab cache, need to be copied to/from userspace. In support of usercopy hardening, this patch defines a region in the ufs_inode_cache slab cache in which userspace copy operations are allowed. This region is known as the slab cache's usercopy region. Slab caches can now check that each copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor [kees: adjust commit log] Signed-off-by: Kees Cook --- fs/ufs/super.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/ufs/super.c b/fs/ufs/super.c index 878cc6264f1a..fa001feed14a 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -1441,11 +1441,14 @@ static void init_once(void *foo) static int __init init_inodecache(void) { - ufs_inode_cachep = kmem_cache_create("ufs_inode_cache", - sizeof(struct ufs_inode_info), - 0, (SLAB_RECLAIM_ACCOUNT| - SLAB_MEM_SPREAD|SLAB_ACCOUNT), - init_once); + ufs_inode_cachep = kmem_cache_create_usercopy("ufs_inode_cache", + sizeof(struct ufs_inode_info), 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| + SLAB_ACCOUNT), + offsetof(struct ufs_inode_info, i_u1.i_symlink), + sizeof_field(struct ufs_inode_info, + i_u1.i_symlink), + init_once); if (ufs_inode_cachep == NULL) return -ENOMEM; return 0; -- 2.7.4