From patchwork Tue Jul 14 18:16:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 11663329 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 110461392 for ; Tue, 14 Jul 2020 18:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0037E227BF for ; Tue, 14 Jul 2020 18:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728370AbgGNSWG (ORCPT ); Tue, 14 Jul 2020 14:22:06 -0400 Received: from smtp-190d.mail.infomaniak.ch ([185.125.25.13]:53153 "EHLO smtp-190d.mail.infomaniak.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725951AbgGNSWG (ORCPT ); Tue, 14 Jul 2020 14:22:06 -0400 X-Greylist: delayed 303 seconds by postgrey-1.27 at vger.kernel.org; Tue, 14 Jul 2020 14:22:05 EDT Received: from smtp-2-0000.mail.infomaniak.ch (unknown [10.5.36.107]) by smtp-2-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4B5pcy2Pf9zlhXmH; Tue, 14 Jul 2020 20:16:50 +0200 (CEST) Received: from localhost (unknown [94.23.54.103]) by smtp-2-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4B5pcv3S84zlh8T3; Tue, 14 Jul 2020 20:16:47 +0200 (CEST) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: linux-kernel@vger.kernel.org Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Aleksa Sarai , Alexei Starovoitov , Al Viro , Andrew Morton , Andy Lutomirski , Christian Brauner , Christian Heimes , Daniel Borkmann , Deven Bowers , Dmitry Vyukov , Eric Biggers , Eric Chiang , Florian Weimer , James Morris , Jan Kara , Jann Horn , Jonathan Corbet , Kees Cook , Lakshmi Ramasubramanian , Matthew Garrett , Matthew Wilcox , Michael Kerrisk , =?utf-8?q?Micka=C3=ABl_Sala=C3=BC?= =?utf-8?q?n?= , Mimi Zohar , =?utf-8?q?Philippe_Tr=C3=A9buchet?= , Scott Shell , Sean Christopherson , Shuah Khan , Steve Dower , Steve Grubb , Tetsuo Handa , Thibaut Sautereau , Vincent Strubel , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v6 1/7] exec: Change uselib(2) IS_SREG() failure to EACCES Date: Tue, 14 Jul 2020 20:16:32 +0200 Message-Id: <20200714181638.45751-2-mic@digikod.net> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200714181638.45751-1-mic@digikod.net> References: <20200714181638.45751-1-mic@digikod.net> MIME-Version: 1.0 X-Antivirus: Dr.Web (R) for Unix mail servers drweb plugin ver.6.0.2.8 X-Antivirus-Code: 0x100000 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Kees Cook 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 Signed-off-by: Kees Cook Acked-by: Christian Brauner Acked-by: Mickaël Salaün Link: https://lore.kernel.org/r/20200605160013.3954297-2-keescook@chromium.org --- fs/exec.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index e6e8a9a70327..d7c937044d10 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -141,11 +141,10 @@ SYSCALL_DEFINE1(uselib, const char __user *, library) 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;