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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BE56C433F5 for ; Wed, 5 Oct 2022 18:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230490AbiJES5f (ORCPT ); Wed, 5 Oct 2022 14:57:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231161AbiJES51 (ORCPT ); Wed, 5 Oct 2022 14:57:27 -0400 Received: from smtp-1908.mail.infomaniak.ch (smtp-1908.mail.infomaniak.ch [185.125.25.8]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C77A87FE5C for ; Wed, 5 Oct 2022 11:57:26 -0700 (PDT) Received: from smtp-2-0000.mail.infomaniak.ch (unknown [10.5.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4MjP2Y1NQXzMqHNX; Wed, 5 Oct 2022 20:57:25 +0200 (CEST) Received: from ns3096276.ip-94-23-54.eu (unknown [23.97.221.149]) by smtp-2-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4MjP2X1PbQzMppDN; Wed, 5 Oct 2022 20:57:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1664996245; bh=ClIUzkJgJhMe65AWwBzAoGWacBocsBcKUgMU0VXLgnE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=si7tj1xRKcd+8mMSKScicxz17ie2RWEteoblQweOyQT/+GIMDHFRK8jhHR0JqP+n1 Glb1G1S7zzK7+AskhvGM3jfN1ZnPxEItmzRCDB5mDfWgAJa5BiKgh9qw/HiOGMw4GF USoG8cloPlq+i8ueCesPrHmKJyjGpMhCOgDMSYKk= Message-ID: <8c5b8019-f945-417f-3f98-ef5c9317b52d@digikod.net> Date: Wed, 5 Oct 2022 20:57:23 +0200 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v8 8/9] samples/landlock: Extend sample tool to support LANDLOCK_ACCESS_FS_TRUNCATE Content-Language: en-US To: =?UTF-8?Q?G=c3=bcnther_Noack?= , linux-security-module@vger.kernel.org Cc: James Morris , Paul Moore , "Serge E . Hallyn" , linux-fsdevel@vger.kernel.org, Konstantin Meskhidze References: <20221001154908.49665-1-gnoack3000@gmail.com> <20221001154908.49665-9-gnoack3000@gmail.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <20221001154908.49665-9-gnoack3000@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 01/10/2022 17:49, Günther Noack wrote: > Update the sandboxer sample to restrict truncate actions. This is > automatically enabled by default if the running kernel supports > LANDLOCK_ACCESS_FS_TRUNCATE, except for the paths listed in the > LL_FS_RW environment variable. > > Signed-off-by: Günther Noack > --- > samples/landlock/sandboxer.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) > > diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c > index 3e404e51ec64..771b6b10d519 100644 > --- a/samples/landlock/sandboxer.c > +++ b/samples/landlock/sandboxer.c > @@ -76,7 +76,8 @@ static int parse_path(char *env_path, const char ***const path_list) > #define ACCESS_FILE ( \ > LANDLOCK_ACCESS_FS_EXECUTE | \ > LANDLOCK_ACCESS_FS_WRITE_FILE | \ > - LANDLOCK_ACCESS_FS_READ_FILE) > + LANDLOCK_ACCESS_FS_READ_FILE | \ > + LANDLOCK_ACCESS_FS_TRUNCATE) > > /* clang-format on */ > > @@ -160,10 +161,8 @@ static int populate_ruleset(const char *const env_var, const int ruleset_fd, > LANDLOCK_ACCESS_FS_MAKE_FIFO | \ > LANDLOCK_ACCESS_FS_MAKE_BLOCK | \ > LANDLOCK_ACCESS_FS_MAKE_SYM | \ > - LANDLOCK_ACCESS_FS_REFER) > - > -#define ACCESS_ABI_2 ( \ > - LANDLOCK_ACCESS_FS_REFER) > + LANDLOCK_ACCESS_FS_REFER | \ > + LANDLOCK_ACCESS_FS_TRUNCATE) > > /* clang-format on */ > > @@ -226,11 +225,17 @@ int main(const int argc, char *const argv[], char *const *const envp) > return 1; > } > /* Best-effort security. */ > - if (abi < 2) { > - ruleset_attr.handled_access_fs &= ~ACCESS_ABI_2; > - access_fs_ro &= ~ACCESS_ABI_2; > - access_fs_rw &= ~ACCESS_ABI_2; You can now base your patches on the current Linus' master branch, these three commits are now merged: https://git.kernel.org/mic/c/2fff00c81d4c37a037cf704d2d219fbcb45aea3c The (inlined) documentation also needs to be updated according to this commit to align with the double backtick convention. > + switch (abi) { > + case 1: > + /* Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2 */ > + ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER; > + __attribute__((fallthrough)); > + case 2: > + /* Removes LANDLOCK_ACCESS_FS_TRUNCATE for ABI < 3 */ > + ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE; > } > + access_fs_ro &= ruleset_attr.handled_access_fs; > + access_fs_rw &= ruleset_attr.handled_access_fs; > > ruleset_fd = > landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);