From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-8fae.mail.infomaniak.ch (smtp-8fae.mail.infomaniak.ch [83.166.143.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3DB87745CB for ; Fri, 13 Sep 2024 16:40:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.166.143.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726245619; cv=none; b=hxPO0ElbqDwyGhbao9rA1UYrm14k2fgBqs575UWEuZxQAnSNKCNnBb/HPwzbmVKlVMeedIZlqS10a7+vB9TOQdOLGIx4AaG3wUAs+j3fz5+lZhIBiReijWMaF9f6NjmJ9nBBzeBaW4cVjv+w2nYj8zs8m27BLphQfVdt0ADzXMU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726245619; c=relaxed/simple; bh=f+359BLhYQ/Pg24mzq1ifHF0ls/rX9zTnkmJM6Jpxkc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RYgPfoWwCdeHeFpgDsD8rnsY/sC+G3cyy+qrlqLMIHdudvTzdSOb9B1/KC1F0l2CzW7IWpJgk7iFkouqxx0eCMWOF7FbfN8pWH/A1Hl8asN6glPutlucQ8oTjihQJ4KSw5/jOjjMBj4quJ5QvOBr0K2xJx6MAGKDS5SXMJBcKQs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net; spf=pass smtp.mailfrom=digikod.net; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b=WIY7Z/3I; arc=none smtp.client-ip=83.166.143.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=digikod.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="WIY7Z/3I" Received: from smtp-3-0000.mail.infomaniak.ch (smtp-3-0000.mail.infomaniak.ch [10.4.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4X50Gw0wvPz9ZT; Fri, 13 Sep 2024 18:33:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digikod.net; s=20191114; t=1726245192; bh=jL3SgGv5TLclTQUubcFPqq833ZrkKmojbZCL1JIDaHg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WIY7Z/3IAa1GQIu+Lv08iD0+3zMhCcwthtjR8rC73MwiT6LKOiStafOZpFbSedAeJ DVXoy+jV6k49dVfznUPANh0X3SbBACoUO38ERyTmWkEyCKp4PvWuPS33Vu6pklZBuA HYn/eLOZsxDQPDEcJiB+Ir1yXUiVUDJLEckTDRCo= Received: from unknown by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4X50Gv0fyVzJ4f; Fri, 13 Sep 2024 18:33:11 +0200 (CEST) Date: Fri, 13 Sep 2024 18:33:03 +0200 From: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= To: Tahera Fahimi Cc: outreachy@lists.linux.dev, gnoack@google.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, bjorn3_gh@protonmail.com, jannh@google.com, netdev@vger.kernel.org Subject: Re: [PATCH v11 0/8] Landlock: Add abstract UNIX socket restriction Message-ID: <20240913.Doof4aiK8soh@digikod.net> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Infomaniak-Routing: alpha I have reworked a bit the patches, including the signal scoping ones, and they are here: https://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git/log/?h=next This is based on a manual merge of some VFS changes and LSM changes required for this patch series: https://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git/commit/?h=next&id=24dfe95e493086a99acf7df1ef23d9f21f8cdec7 My changes are explained in the "[mic: ...]" part of the commit messages. Please send two last patch series, with this changes and reply to it with your comments if any. On Wed, Sep 04, 2024 at 06:13:54PM -0600, Tahera Fahimi wrote: > This patch series adds scoping mechanism for abstract UNIX sockets. > Closes: https://github.com/landlock-lsm/linux/issues/7 > > Problem > ======= > > Abstract UNIX sockets are used for local inter-process communications > independent of the filesystem. Currently, a sandboxed process can > connect to a socket outside of the sandboxed environment, since Landlock > has no restriction for connecting to an abstract socket address(see more > details in [1,2]). Access to such sockets for a sandboxed process should > be scoped the same way ptrace is limited. > > [1] https://lore.kernel.org/all/20231023.ahphah4Wii4v@digikod.net/ > [2] https://lore.kernel.org/all/20231102.MaeWaepav8nu@digikod.net/ > > Solution > ======== > > To solve this issue, we extend the user space interface by adding a new > "scoped" field to Landlock ruleset attribute structure. This field can > contains different rights to restrict different functionalities. For > abstract UNIX sockets, we introduce > "LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET" field to specify that a ruleset > will deny any connection from within the sandbox domain to its parent > (i.e. any parent sandbox or non-sandbox processes). > > Example > ======= > > Starting a listening socket with socat(1): > socat abstract-listen:mysocket - > > Starting a sandboxed shell from $HOME with samples/landlock/sandboxer: > LL_FS_RO=/ LL_FS_RW=. LL_SCOPED="a" ./sandboxer /bin/bash > > If we try to connect to the listening socket, the connection gets > refused. > socat - abstract-connect:mysocket --> fails > > > Notes of Implementation > ======================= > > * Using the "scoped" field provides enough compatibility and flexibility > to extend the scoping mechanism for other IPCs(e.g. signals). > > * To access the domain of a socket, we use its credentials of the file's > FD which point to the credentials of the process that created the > socket (see more details in [3]). Cases where the process using the > socket has a different domain than the process created it are covered > in the "outside_socket" test. > > [3]https://lore.kernel.org/all/20240611.Pi8Iph7ootae@digikod.net/ > > Previous Versions > ================= > v10:https://lore.kernel.org/all/cover.1724125513.git.fahimitahera@gmail.com/ > v9: https://lore.kernel.org/all/cover.1723615689.git.fahimitahera@gmail.com/ > v8: https://lore.kernel.org/all/cover.1722570749.git.fahimitahera@gmail.com/ > v7: https://lore.kernel.org/all/cover.1721269836.git.fahimitahera@gmail.com/ > v6: https://lore.kernel.org/all/Zn32CYZiu7pY+rdI@tahera-OptiPlex-5000/ > and https://lore.kernel.org/all/Zn32KKIJrY7Zi51K@tahera-OptiPlex-5000/ > v5: https://lore.kernel.org/all/ZnSZnhGBiprI6FRk@tahera-OptiPlex-5000/ > v4: https://lore.kernel.org/all/ZnNcE3ph2SWi1qmd@tahera-OptiPlex-5000/ > v3: https://lore.kernel.org/all/ZmJJ7lZdQuQop7e5@tahera-OptiPlex-5000/ > v2: https://lore.kernel.org/all/ZgX5TRTrSDPrJFfF@tahera-OptiPlex-5000/ > v1: https://lore.kernel.org/all/ZgXN5fi6A1YQKiAQ@tahera-OptiPlex-5000/ > > Tahera Fahimi (8): > Landlock: Add abstract UNIX socket restriction > selftests/landlock: Add test for handling unknown scope > selftests/landlock: Add abstract UNIX socket restriction tests > selftests/landlock: Add tests for UNIX sockets with any address > formats > selftests/landlock: Test connected vs non-connected datagram UNIX > socket > selftests/landlock: Restrict inherited datagram UNIX socket to connect > sample/landlock: Add support abstract UNIX socket restriction > Landlock: Document LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET and ABI > version > > Documentation/userspace-api/landlock.rst | 45 +- > include/uapi/linux/landlock.h | 28 + > samples/landlock/sandboxer.c | 61 +- > security/landlock/limits.h | 3 + > security/landlock/ruleset.c | 7 +- > security/landlock/ruleset.h | 24 +- > security/landlock/syscalls.c | 17 +- > security/landlock/task.c | 136 +++ > tools/testing/selftests/landlock/base_test.c | 2 +- > tools/testing/selftests/landlock/common.h | 38 + > tools/testing/selftests/landlock/net_test.c | 31 +- > .../landlock/scoped_abstract_unix_test.c | 993 ++++++++++++++++++ > .../selftests/landlock/scoped_base_variants.h | 154 +++ > .../selftests/landlock/scoped_common.h | 28 + > .../scoped_multiple_domain_variants.h | 154 +++ > .../testing/selftests/landlock/scoped_test.c | 33 + > 16 files changed, 1709 insertions(+), 45 deletions(-) > create mode 100644 tools/testing/selftests/landlock/scoped_abstract_unix_test.c > create mode 100644 tools/testing/selftests/landlock/scoped_base_variants.h > create mode 100644 tools/testing/selftests/landlock/scoped_common.h > create mode 100644 tools/testing/selftests/landlock/scoped_multiple_domain_variants.h > create mode 100644 tools/testing/selftests/landlock/scoped_test.c > > -- > 2.34.1 >