From patchwork Wed Aug 14 03:01:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mikhail Ivanov X-Patchwork-Id: 13762792 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (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 618A9757F3; Wed, 14 Aug 2024 03:02:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723604541; cv=none; b=pw5jb+zN4GbWyUZ0sdnFLg4NCdFEs8IUpLMMsWo9/2sRMpXQ522K0c6bz4z0huKKosl35uUcR2blQ/nH7EfGUA47YDeN+PRW+qgWJ/y3P5bxhavMfXu8gHNaFl/8HMn6onyOysAjCXkepxvm8Ze+R+GrkGSSYpIbl2WrQm6ChdY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723604541; c=relaxed/simple; bh=rSiJD6CB325ZcboYhNJAZRZM+QHB/FdTNMAAaT83eAE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LNmfNkBwGwmdSbvvBwZrjNYJzFULFvzAeE3E4u0+wmO9kbgoANry6iEtMeJr1760PDNcKSNzzsw1gFCR3ltl5w3YmdzWDUYb4HnuzAGjRA9LwbXValfHGSyTf2BRt55l8ylHJfaoVOZsmSS3q5D2DqYItW+tZd2lfvnyJDcs0XI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei-partners.com; spf=pass smtp.mailfrom=huawei-partners.com; arc=none smtp.client-ip=45.249.212.35 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei-partners.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei-partners.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4WkCbS5grKz1S7k1; Wed, 14 Aug 2024 10:57:24 +0800 (CST) Received: from dggpemm500020.china.huawei.com (unknown [7.185.36.49]) by mail.maildlp.com (Postfix) with ESMTPS id B461C1402CF; Wed, 14 Aug 2024 11:02:16 +0800 (CST) Received: from mscphis02103.huawei.com (10.123.65.215) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 14 Aug 2024 11:02:14 +0800 From: Mikhail Ivanov To: CC: , , , , , , , Subject: [RFC PATCH v2 9/9] samples/landlock: Support LANDLOCK_ACCESS_NET_LISTEN Date: Wed, 14 Aug 2024 11:01:51 +0800 Message-ID: <20240814030151.2380280-10-ivanov.mikhail1@huawei-partners.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240814030151.2380280-1-ivanov.mikhail1@huawei-partners.com> References: <20240814030151.2380280-1-ivanov.mikhail1@huawei-partners.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: mscpeml500004.china.huawei.com (7.188.26.250) To dggpemm500020.china.huawei.com (7.185.36.49) Extend sample with TCP listen control logic. Signed-off-by: Mikhail Ivanov Reviewed-by: Günther Noack --- samples/landlock/sandboxer.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c index e8223c3e781a..3f50cb3f8039 100644 --- a/samples/landlock/sandboxer.c +++ b/samples/landlock/sandboxer.c @@ -55,6 +55,7 @@ static inline int landlock_restrict_self(const int ruleset_fd, #define ENV_FS_RW_NAME "LL_FS_RW" #define ENV_TCP_BIND_NAME "LL_TCP_BIND" #define ENV_TCP_CONNECT_NAME "LL_TCP_CONNECT" +#define ENV_TCP_LISTEN_NAME "LL_TCP_LISTEN" #define ENV_DELIMITER ":" static int parse_path(char *env_path, const char ***const path_list) @@ -208,7 +209,7 @@ static int populate_ruleset_net(const char *const env_var, const int ruleset_fd, /* clang-format on */ -#define LANDLOCK_ABI_LAST 5 +#define LANDLOCK_ABI_LAST 6 int main(const int argc, char *const argv[], char *const *const envp) { @@ -222,15 +223,16 @@ int main(const int argc, char *const argv[], char *const *const envp) struct landlock_ruleset_attr ruleset_attr = { .handled_access_fs = access_fs_rw, .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP | - LANDLOCK_ACCESS_NET_CONNECT_TCP, + LANDLOCK_ACCESS_NET_CONNECT_TCP | + LANDLOCK_ACCESS_NET_LISTEN_TCP, }; if (argc < 2) { fprintf(stderr, - "usage: %s=\"...\" %s=\"...\" %s=\"...\" %s=\"...\"%s " + "usage: %s=\"...\" %s=\"...\" %s=\"...\" %s=\"...\" %s=\"...\"%s " " [args]...\n\n", ENV_FS_RO_NAME, ENV_FS_RW_NAME, ENV_TCP_BIND_NAME, - ENV_TCP_CONNECT_NAME, argv[0]); + ENV_TCP_CONNECT_NAME, ENV_TCP_LISTEN_NAME, argv[0]); fprintf(stderr, "Execute a command in a restricted environment.\n\n"); fprintf(stderr, @@ -251,15 +253,19 @@ int main(const int argc, char *const argv[], char *const *const envp) fprintf(stderr, "* %s: list of ports allowed to connect (client).\n", ENV_TCP_CONNECT_NAME); + fprintf(stderr, + "* %s: list of ports allowed to listen (server).\n", + ENV_TCP_LISTEN_NAME); fprintf(stderr, "\nexample:\n" "%s=\"${PATH}:/lib:/usr:/proc:/etc:/dev/urandom\" " "%s=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" " "%s=\"9418\" " "%s=\"80:443\" " + "%s=\"9418\" " "%s bash -i\n\n", ENV_FS_RO_NAME, ENV_FS_RW_NAME, ENV_TCP_BIND_NAME, - ENV_TCP_CONNECT_NAME, argv[0]); + ENV_TCP_CONNECT_NAME, ENV_TCP_LISTEN_NAME, argv[0]); fprintf(stderr, "This sandboxer can use Landlock features " "up to ABI version %d.\n", @@ -326,6 +332,11 @@ int main(const int argc, char *const argv[], char *const *const envp) case 4: /* Removes LANDLOCK_ACCESS_FS_IOCTL_DEV for ABI < 5 */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_IOCTL_DEV; + __attribute__((fallthrough)); + case 5: + /* Removes LANDLOCK_ACCESS_NET_LISTEN support for ABI < 6 */ + ruleset_attr.handled_access_net &= + ~(LANDLOCK_ACCESS_NET_LISTEN_TCP); fprintf(stderr, "Hint: You should update the running kernel " @@ -357,6 +368,12 @@ int main(const int argc, char *const argv[], char *const *const envp) ruleset_attr.handled_access_net &= ~LANDLOCK_ACCESS_NET_CONNECT_TCP; } + /* Removes listen access attribute if not supported by a user. */ + env_port_name = getenv(ENV_TCP_LISTEN_NAME); + if (!env_port_name) { + ruleset_attr.handled_access_net &= + ~LANDLOCK_ACCESS_NET_LISTEN_TCP; + } ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); @@ -380,6 +397,10 @@ int main(const int argc, char *const argv[], char *const *const envp) LANDLOCK_ACCESS_NET_CONNECT_TCP)) { goto err_close_ruleset; } + if (populate_ruleset_net(ENV_TCP_LISTEN_NAME, ruleset_fd, + LANDLOCK_ACCESS_NET_LISTEN_TCP)) { + goto err_close_ruleset; + } if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { perror("Failed to restrict privileges");