From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753023AbdFSXkt (ORCPT ); Mon, 19 Jun 2017 19:40:49 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:32814 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752582AbdFSXgs (ORCPT ); Mon, 19 Jun 2017 19:36:48 -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 03/23] vfs: define usercopy region in names_cache slab caches Date: Mon, 19 Jun 2017 16:36:17 -0700 Message-Id: <1497915397-93805-4-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 vfs pathnames stored internally in inodes and contained in the names_cache slab cache need to be copied to/from userspace. In support of usercopy hardening, this patch defines the entire cache object in the names_cache slab cache as whitelisted, since it holds name strings to be copied to userspace. This patch is verbatim 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/dcache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index cddf39777835..f7f3c4114baa 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -3616,8 +3616,8 @@ void __init vfs_caches_init_early(void) void __init vfs_caches_init(void) { - names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0, - SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + names_cachep = kmem_cache_create_usercopy("names_cache", PATH_MAX, 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, 0, PATH_MAX, NULL); dcache_init(); inode_init(); -- 2.7.4