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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3487DC4743C for ; Wed, 23 Jun 2021 13:41:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C760D61026 for ; Wed, 23 Jun 2021 13:41:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C760D61026 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AE0B96B006C; Wed, 23 Jun 2021 09:41:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A8FC66B0070; Wed, 23 Jun 2021 09:41:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9305F8D0001; Wed, 23 Jun 2021 09:41:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0141.hostedemail.com [216.40.44.141]) by kanga.kvack.org (Postfix) with ESMTP id 5704B6B006C for ; Wed, 23 Jun 2021 09:41:53 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 93C64181AEF1F for ; Wed, 23 Jun 2021 13:41:53 +0000 (UTC) X-FDA: 78285101706.28.352E3F5 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf13.hostedemail.com (Postfix) with ESMTP id 23B94E000273 for ; Wed, 23 Jun 2021 13:41:53 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id C12CF61076; Wed, 23 Jun 2021 13:41:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624455712; bh=ahAIQzGeIV5bSA+izmWMgZyiMYHJ37sy5dm5nG35WsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Q2fs3xfj1k5ez23+zg+C8YgfDHiuth2aI+p7UqiOQwWK2sSAqUXxaqnpFRxiPL+Vu yrIX6Ii4gw63FUm9vIRgoLmKYmuxHFoLda7MqkRAbTnqhzc8v3FehQkcyzXhtl1rlC Vbk1eDjCtC15gwnY0osT+KmneZmHey/NlU4Kb5RG3t5fnUlFwxQ9Ybknkx4qBd74jn BLx467xAqWjRurwe/dOHVwf+46JGH25SbcJFgG0mKWWOQWaCgqezEYEFGPFPTNi4X1 zIvAmd7tAe+ovpIG9dYW6RilEpCxGJiBD3U9PxvlYX2rh7w/At/AArTHZ1JuWpbVh6 867z2BiQTgPkQ== Date: Wed, 23 Jun 2021 16:41:50 +0300 From: Jarkko Sakkinen To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, tim.gardner@canonical.com, reinette.chatre@intel.com, shuah@kernel.org, linux-sgx@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH] selftests/sgx: remove checks for file execute permissions Message-ID: <20210623134150.j4qjhcepmtohsxdo@kernel.org> References: <20210621190556.4B5DCBB1@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210621190556.4B5DCBB1@viggo.jf.intel.com> X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 23B94E000273 Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Q2fs3xfj; spf=pass (imf13.hostedemail.com: domain of jarkko@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=jarkko@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: fztcmg3xj74q31yd693kse4xsr5hufcr X-HE-Tag: 1624455713-743989 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jun 21, 2021 at 12:05:56PM -0700, Dave Hansen wrote: > > The SGX selftests can fail for a bunch of non-obvious reasons > like 'noexec' permissions on /dev (which is the default *EVERYWHERE* > it seems). > > A new test mistakenly also looked for +x permission on the > /dev/sgx_enclave. File execute permissions really only apply to > the ability of execve() to work on a file, *NOT* on the ability > for an application to map the file with PROT_EXEC. SGX needs to > mmap(PROT_EXEC), but doesn't need to execve() the device file. > > Remove the check. > > Fixes: 4284f7acb78b ("selftests/sgx: Improve error detection and messages") > Reported-by: Tim Gardner > Cc: Jarkko Sakkinen > Cc: Reinette Chatre > Cc: Dave Hansen > Cc: Shuah Khan > Cc: linux-sgx@vger.kernel.org > Cc: linux-kselftest@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > --- > > b/tools/testing/selftests/sgx/load.c | 16 +++------------- > 1 file changed, 3 insertions(+), 13 deletions(-) > > diff -puN tools/testing/selftests/sgx/load.c~sgx-no-file-exec tools/testing/selftests/sgx/load.c > --- a/tools/testing/selftests/sgx/load.c~sgx-no-file-exec 2021-06-21 11:48:25.226294281 -0700 > +++ b/tools/testing/selftests/sgx/load.c 2021-06-21 12:03:28.023292029 -0700 > @@ -150,16 +150,6 @@ bool encl_load(const char *path, struct > goto err; > } > > - /* > - * This just checks if the /dev file has these permission > - * bits set. It does not check that the current user is > - * the owner or in the owning group. > - */ > - if (!(sb.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))) { > - fprintf(stderr, "no execute permissions on device file %s\n", device_path); > - goto err; > - } > - > ptr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0); > if (ptr == (void *)-1) { > perror("mmap for read"); > @@ -169,13 +159,13 @@ bool encl_load(const char *path, struct > > #define ERR_MSG \ > "mmap() succeeded for PROT_READ, but failed for PROT_EXEC.\n" \ > -" Check that current user has execute permissions on %s and \n" \ > -" that /dev does not have noexec set: mount | grep \"/dev .*noexec\"\n" \ > +" Check that /dev does not have noexec set:\n" \ > +" \tmount | grep \"/dev .*noexec\"\n" \ > " If so, remount it executable: mount -o remount,exec /dev\n\n" > > ptr = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_SHARED, fd, 0); > if (ptr == (void *)-1) { > - fprintf(stderr, ERR_MSG, device_path); > + fprintf(stderr, ERR_MSG); > goto err; > } > munmap(ptr, PAGE_SIZE); > _ > Reviewed-by: Jarkko Sakkinen /Jarkko