From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD440C31E4B for ; Fri, 14 Jun 2019 20:28:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E040217F9 for ; Fri, 14 Jun 2019 20:28:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544125; bh=94ECcV6dTx0xMKW52GxZHCimBf4x1MEXzsL6Zr2qNAc=; h=From:To:Cc:Subject:Date:List-ID:From; b=ztd+EzIBsZUWwB6aCEdcU0cIqCfogGqUhyJQW1sP5bUQMGhqL2HkrFezC2EjNqd93 5r2ThaFvvTn7uKheo8DsAmpE3rjK84z/A44nTQTWS80Br0ASTjONBXjnBFhRieKhT4 CnHIyY5D7ATPTv7uOpS/8ged7AUe11JsyOlGQxyk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726028AbfFNU2o (ORCPT ); Fri, 14 Jun 2019 16:28:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:50198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725991AbfFNU2o (ORCPT ); Fri, 14 Jun 2019 16:28:44 -0400 Received: from sasha-vm.mshome.net (unknown [131.107.159.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 168A2217F9; Fri, 14 Jun 2019 20:28:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544124; bh=94ECcV6dTx0xMKW52GxZHCimBf4x1MEXzsL6Zr2qNAc=; h=From:To:Cc:Subject:Date:From; b=hBijiaGH3A/Rs5sPj2DV+lkVp/wiL0V2sMx43NUwmOhbL2IYW6K/DYgTRt2/SO53a j4g38R6cBVlnv+1TX41IVuPzoD38imzFrv7sXmqY7GmUry2buu055w6oHLruwUVK0H qOaof/OUE6h9oQOCf41jrTVdffGd43lGudt1vvjA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , Sasha Levin Subject: [PATCH AUTOSEL 5.1 01/59] lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical Date: Fri, 14 Jun 2019 16:27:45 -0400 Message-Id: <20190614202843.26941-1-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kees Cook [ Upstream commit 2bf8496f6e9b7e9a557f65eb95eab16fea7958c7 ] The prior implementation of the KERNEL_DS fault checking would work on any unmapped kernel address, but this was narrowed to the non-canonical range instead. This adjusts the LKDTM test to match. Fixes: 00c42373d397 ("x86-64: add warning for non-canonical user access address dereferences") Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- drivers/misc/lkdtm/usercopy.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c index d5a0e7f1813b..e172719dd86d 100644 --- a/drivers/misc/lkdtm/usercopy.c +++ b/drivers/misc/lkdtm/usercopy.c @@ -324,14 +324,16 @@ void lkdtm_USERCOPY_KERNEL(void) void lkdtm_USERCOPY_KERNEL_DS(void) { - char __user *user_ptr = (char __user *)ERR_PTR(-EINVAL); + char __user *user_ptr = + (char __user *)(0xFUL << (sizeof(unsigned long) * 8 - 4)); mm_segment_t old_fs = get_fs(); char buf[10] = {0}; - pr_info("attempting copy_to_user on unmapped kernel address\n"); + pr_info("attempting copy_to_user() to noncanonical address: %px\n", + user_ptr); set_fs(KERNEL_DS); - if (copy_to_user(user_ptr, buf, sizeof(buf))) - pr_info("copy_to_user un unmapped kernel address failed\n"); + if (copy_to_user(user_ptr, buf, sizeof(buf)) == 0) + pr_err("copy_to_user() to noncanonical address succeeded!?\n"); set_fs(old_fs); } -- 2.20.1