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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 46721C433DF for ; Wed, 12 Aug 2020 01:36:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 167822054F for ; Wed, 12 Aug 2020 01:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597196186; bh=KgncLYKpqu/RmWUdVNRmLaaRy/rMBRfitfw01Ejfz34=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=Icxk/ziWw/Ek/shbY7X+osh4oCNI4PtQZTK+frmavv/UkZlrlQBwXQMfnCk8cSjcP KS/Y3/Nn+HntxS8S6JZ+SGbLa7FMbhB2hyNJTMpahl2xHMnVGxQNnj1FAVmbsOq/gb LBdTtmsN3e6IxRn0L5qJ+Rw71Dr7tEyjnGwza1fo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726488AbgHLBgZ (ORCPT ); Tue, 11 Aug 2020 21:36:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:37752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726143AbgHLBgZ (ORCPT ); Tue, 11 Aug 2020 21:36:25 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3FBE20658; Wed, 12 Aug 2020 01:36:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597196184; bh=KgncLYKpqu/RmWUdVNRmLaaRy/rMBRfitfw01Ejfz34=; h=Date:From:To:Subject:In-Reply-To:From; b=NaRj0w6hiLBLw9GxjCrOzchy5BOhIv4CykRq8N2igNwN/o/Ur/fjhvfp/bqKH98bs 35pahhdYnH/SGMPX+zYKmofJXGD2aSa0LzhWPL7WFOa8ecCZTRES8cgCbL0GMmWEzq NWKtBDECWuoE7cN15Vm0nbVQm/YV/GvanX0gAIgo= Date: Tue, 11 Aug 2020 18:36:23 -0700 From: Andrew Morton To: akpm@linux-foundation.org, christian.brauner@ubuntu.com, cyphar@cyphar.com, dvyukov@google.com, ebiggers3@gmail.com, keescook@chromium.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Subject: [patch 116/165] exec: change uselib(2) IS_SREG() failure to EACCES Message-ID: <20200812013623.YcT2xx-Hb%akpm@linux-foundation.org> In-Reply-To: <20200811182949.e12ae9a472e3b5e27e16ad6c@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Kees Cook Subject: exec: change uselib(2) IS_SREG() failure to EACCES Patch series "Relocate execve() sanity checks", v2. While looking at the code paths for the proposed O_MAYEXEC flag, I saw some things that looked like they should be fixed up. exec: Change uselib(2) IS_SREG() failure to EACCES This just regularizes the return code on uselib(2). exec: Move S_ISREG() check earlier This moves the S_ISREG() check even earlier than it was already. exec: Move path_noexec() check earlier This adds the path_noexec() check to the same place as the S_ISREG() check. This patch (of 3): Change uselib(2)' S_ISREG() error return to EACCES instead of EINVAL so the behavior matches execve(2), and the seemingly documented value. The "not a regular file" failure mode of execve(2) is explicitly documented[1], but it is not mentioned in uselib(2)[2] which does, however, say that open(2) and mmap(2) errors may apply. The documentation for open(2) does not include a "not a regular file" error[3], but mmap(2) does[4], and it is EACCES. [1] http://man7.org/linux/man-pages/man2/execve.2.html#ERRORS [2] http://man7.org/linux/man-pages/man2/uselib.2.html#ERRORS [3] http://man7.org/linux/man-pages/man2/open.2.html#ERRORS [4] http://man7.org/linux/man-pages/man2/mmap.2.html#ERRORS Link: http://lkml.kernel.org/r/20200605160013.3954297-1-keescook@chromium.org Link: http://lkml.kernel.org/r/20200605160013.3954297-2-keescook@chromium.org Signed-off-by: Kees Cook Acked-by: Christian Brauner Cc: Aleksa Sarai Cc: Alexander Viro Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Tetsuo Handa Signed-off-by: Andrew Morton --- fs/exec.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/fs/exec.c~exec-change-uselib2-is_sreg-failure-to-eacces +++ a/fs/exec.c @@ -141,11 +141,10 @@ SYSCALL_DEFINE1(uselib, const char __use if (IS_ERR(file)) goto out; - error = -EINVAL; + error = -EACCES; if (!S_ISREG(file_inode(file)->i_mode)) goto exit; - error = -EACCES; if (path_noexec(&file->f_path)) goto exit; _