Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752007AbdITUqX (ORCPT ); Wed, 20 Sep 2017 16:46:23 -0400 Received: from mail-pg0-f41.google.com ([74.125.83.41]:56523 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751932AbdITUqO (ORCPT ); Wed, 20 Sep 2017 16:46:14 -0400 X-Google-Smtp-Source: AOwi7QBeF4XE3RC/jm1ungl235aGF2O8qubaS7Hhsvw6JXmDKu0o1gUJa6HnDsW7w11pArmSTLNEHQ== From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , "David S. Miller" , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Subject: [PATCH v3 20/31] caif: Define usercopy region in caif proto slab cache Date: Wed, 20 Sep 2017 13:45:26 -0700 Message-Id: <1505940337-79069-21-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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1745 Lines: 47 From: David Windsor The CAIF channel connection request parameters need to be copied to/from userspace. In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. example usage trace: net/caif/caif_socket.c: setsockopt(...): ... copy_from_user(&cf_sk->conn_req.param.data, ..., ol) 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: split from network patch, provide usage trace] Cc: "David S. Miller" Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook --- net/caif/caif_socket.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 632d5a416d97..c76d513b9a7a 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -1032,6 +1032,8 @@ static int caif_create(struct net *net, struct socket *sock, int protocol, static struct proto prot = {.name = "PF_CAIF", .owner = THIS_MODULE, .obj_size = sizeof(struct caifsock), + .useroffset = offsetof(struct caifsock, conn_req.param), + .usersize = sizeof_field(struct caifsock, conn_req.param) }; if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) -- 2.7.4