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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 F38CBC2D0C0 for ; Fri, 20 Dec 2019 15:42:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB2F62467F for ; Fri, 20 Dec 2019 15:42:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="CG0ZvaL7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbfLTPmq (ORCPT ); Fri, 20 Dec 2019 10:42:46 -0500 Received: from mail-wr1-f68.google.com ([209.85.221.68]:42579 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727587AbfLTPmQ (ORCPT ); Fri, 20 Dec 2019 10:42:16 -0500 Received: by mail-wr1-f68.google.com with SMTP id q6so9816666wro.9 for ; Fri, 20 Dec 2019 07:42:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sAPx/qSpknm81mAjK6n50HYFMwR3Dc07XTjZ/N5q/14=; b=CG0ZvaL7Wd/DINrzFx+GeaXy7K63Erl9nn+5LqdgxsYGqiksVxbrDXCAu0fVki91kB GtQSHKuvsDqmk2cvFiy4Jmigdc02sK/KydIMyIe9ttsFEfpjkI3RPrpYL/hJjPuoA0N7 JYlOP0PBy1DmUbV0WL051NdvQkki4QAFHG480= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sAPx/qSpknm81mAjK6n50HYFMwR3Dc07XTjZ/N5q/14=; b=shHzWcw7c6QnyotzMS4aOamDrsVm7kei2+jkvKfTFSg2GSNvbgUdKwyzCpOygd3bx7 VNuzMtvr1D81pRB0eoevoiv7OUdVCrmQEuO7dEKYxyOtdPWEmNWw36aKEK0WCssTGwhh T+t36PF3mfFMFMZ8/Zsz6rFWrxGocPhYWE2Q5Ak/I1FEciyZWjIjebxnxsmERPX7mw0T 2oX2nNeK7i7TPJB+07Ua+9OV+kTTd/ynBU5J8MuLmX4oXYBw8IMAqV4ijZeVcD41waNn FaLRUSwObVsnQwDMqtI5U31B5jOLMcMTizjALgnuEnyXTz+sRo9ZnRmwoQqmgwsM20Td iTRQ== X-Gm-Message-State: APjAAAVZTPRiBYc0ZWPw+ReqgMDIw1j7MFzzZQwl9pNLMXWlrGUX6nOH UYguUcYQcVyDx/A2IsNZdBMMXA== X-Google-Smtp-Source: APXvYqxw9sxOQDAQeXYFvHsJkOAe+9rfbeVVbI7uTVCrv/2zfc5kXXzi/J5NgL/9VhQqjLKQZkd8pQ== X-Received: by 2002:a5d:4045:: with SMTP id w5mr14951352wrp.59.1576856533909; Fri, 20 Dec 2019 07:42:13 -0800 (PST) Received: from kpsingh-kernel.localdomain ([2a00:79e1:abc:308:c46b:b838:66cf:6204]) by smtp.gmail.com with ESMTPSA id x11sm10118062wmg.46.2019.12.20.07.42.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Dec 2019 07:42:13 -0800 (PST) From: KP Singh To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , James Morris , Kees Cook , Thomas Garnier , Michael Halcrow , Paul Turner , Brendan Gregg , Jann Horn , Matthew Garrett , Christian Brauner , =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , Florent Revest , Brendan Jackman , Martin KaFai Lau , Song Liu , Yonghong Song , "Serge E. Hallyn" , Mauro Carvalho Chehab , "David S. Miller" , Greg Kroah-Hartman , Nicolas Ferre , Stanislav Fomichev , Quentin Monnet , Andrey Ignatov , Joe Stringer Subject: [PATCH bpf-next v1 08/13] bpf: lsm: Show attached program names in hook read handler. Date: Fri, 20 Dec 2019 16:42:03 +0100 Message-Id: <20191220154208.15895-9-kpsingh@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191220154208.15895-1-kpsingh@chromium.org> References: <20191220154208.15895-1-kpsingh@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: KP Singh For inspectability the system administrator should be able to view the list of active KRSI programs: bash # cat /sys/kernel/security/bpf/bprm_check_security bpf_prog1 Signed-off-by: KP Singh --- security/bpf/lsm_fs.c | 81 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 80 insertions(+), 1 deletion(-) diff --git a/security/bpf/lsm_fs.c b/security/bpf/lsm_fs.c index b271e9582d0f..01a89bce1347 100644 --- a/security/bpf/lsm_fs.c +++ b/security/bpf/lsm_fs.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -19,7 +20,85 @@ static struct dentry *bpf_lsm_dir; -static const struct file_operations hook_ops = {}; +static void *seq_start(struct seq_file *m, loff_t *pos) + __acquires(RCU) +{ + struct bpf_prog_array_item *item; + struct bpf_prog_array *progs; + struct bpf_lsm_hook *h; + struct dentry *dentry; + + /* + * rcu_read_lock() must be held before any return statement because the + * stop() will always be called and thus call rcu_read_unlock() + */ + rcu_read_lock(); + + dentry = file_dentry(m->file); + h = dentry->d_fsdata; + if (WARN_ON(!h)) + return ERR_PTR(-EFAULT); + + progs = rcu_dereference(h->progs); + if (!progs) + return NULL; + + /* Assumes that no &dummy_bpf_prog entries exist */ + if ((*pos) >= bpf_prog_array_length(progs)) + return NULL; + + item = progs->items + *pos; + if (!item->prog) + return NULL; + + return item; +} + +static void *seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct bpf_prog_array_item *item = v; + + item++; + ++*pos; + + if (!item->prog) + return NULL; + + return item; +} + +static void seq_stop(struct seq_file *m, void *v) + __releases(RCU) +{ + rcu_read_unlock(); +} + +static int show_prog(struct seq_file *m, void *v) +{ + struct bpf_prog_array_item *item = v; + + seq_printf(m, "%s\n", item->prog->aux->name); + return 0; +} + +static const struct seq_operations hook_seq_ops = { + .show = show_prog, + .start = seq_start, + .next = seq_next, + .stop = seq_stop, +}; + +static int hook_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &hook_seq_ops); +} + +static const struct file_operations hook_ops = { + .open = hook_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; int bpf_lsm_fs_initialized; -- 2.20.1