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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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,USER_IN_DEF_DKIM_WL 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 5CCEFC433DF for ; Mon, 17 Aug 2020 17:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2368420657 for ; Mon, 17 Aug 2020 17:28:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Gy44oW7f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389122AbgHQR2v (ORCPT ); Mon, 17 Aug 2020 13:28:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389322AbgHQRKT (ORCPT ); Mon, 17 Aug 2020 13:10:19 -0400 Received: from mail-ej1-x649.google.com (mail-ej1-x649.google.com [IPv6:2a00:1450:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC315C061348 for ; Mon, 17 Aug 2020 10:08:44 -0700 (PDT) Received: by mail-ej1-x649.google.com with SMTP id gg11so5790678ejb.6 for ; Mon, 17 Aug 2020 10:08:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=EPrw5RnVluwXxcHuirD84lbrde8q2sR6O2SJbUiYZDY=; b=Gy44oW7fKCqNOu7gPn6b5s9Hw32Xq4yvq7Q8/WI+rSdRN/RrnCMqHlZokwohf6GGkz ypoB6AUHgyfz+bJDXMWm8Blt0UBD6/dGaIuQIvfl7bOt3jN4vxXJTDu2jOpZ4ewyPhrG YfljJu3kjA2wyvHtPaCjKBwl0przKWbYzsWQsdGdnLc4hfFX787wguDrmO4kprYWkhbv 9kmWDpjQzVkL2fxSU9KyBkHzj+rX/3HVxRRYRvYLEYt0N4IA1YunVE4CE5wFA26dT5Sn rUrfV1QDNrPwEPvMO5NDiStCmjaz0+nUPq4iRWwIJvzH0bytnrQlfiDS2GHAcmp5HOLN S45A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=EPrw5RnVluwXxcHuirD84lbrde8q2sR6O2SJbUiYZDY=; b=OymIp5KVJs6p8BIYjAd4nFnGST8LR7E2RXIZEnF6vxPNQ2XXsSxnfwojpAq4KxQKxB k+jjsLS5K/mKiUnVHclE1qeb4zHUbX/pZ+X0rbRveQD5Wxo+EzFxElLsSIO3tjC0Gzhx Cx9fy/EtIURH8FOOJ59ubsybk6bQ7LxLd0MlEfsqPIvU4q3XA3fKEZzYM821F5PNZLew 2sqK9AQi5Xjt/fYjQf3Quo0/fv2AftbjRH3UpjBrCAsvqi72l5jtSEo/o70RnNBBCRcQ xDPVaC8JCKkaPlSA+X0lic5tYsYC9gHAeW8liz+wR72X9COaeLsUVkQWhe4OIDPvjTbX xZ7A== X-Gm-Message-State: AOAM533aHmIAUtiUS9LbxBmF/XD9Eq6k7pyyNYECTaXaXElBnsk5+yMQ 9/F3pOcUZbVd0ZP5DjB8ESDqqP9Arw== X-Google-Smtp-Source: ABdhPJybsAInpFNA74sYWytsOjuXY3Qmc09wmwcrpFe5e0ysRNhDs7qvPGChjMLprINFNMZKElFXgEgVXg== X-Received: by 2002:aa7:da46:: with SMTP id w6mr16086222eds.7.1597684122851; Mon, 17 Aug 2020 10:08:42 -0700 (PDT) Date: Mon, 17 Aug 2020 19:07:13 +0200 In-Reply-To: <20200817170729.2605279-1-tweek@google.com> Message-Id: <20200817170729.2605279-3-tweek@google.com> Mime-Version: 1.0 References: <20200817170729.2605279-1-tweek@google.com> X-Mailer: git-send-email 2.28.0.220.ged08abb693-goog Subject: [PATCH v3 2/3] selinux: add basic filtering for audit trace events From: "=?UTF-8?q?Thi=C3=A9baud=20Weksteen?=" To: Paul Moore Cc: Nick Kralevich , Peter Enderborg , "=?UTF-8?q?Thi=C3=A9baud=20Weksteen?=" , Stephen Smalley , Eric Paris , Steven Rostedt , Ingo Molnar , Mauro Carvalho Chehab , "David S. Miller" , Rob Herring , linux-kernel@vger.kernel.org, selinux@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Enderborg This patch adds further attributes to the event. These attributes are helpful to understand the context of the message and can be used to filter the events. There are three common items. Source context, target context and tclass. There are also items from the outcome of operation performed. An event is similar to: <...>-1309 [002] .... 6346.691689: selinux_audited: requested=3D0x4000000 denied=3D0x4000000 audited=3D0x4000000 result=3D-13 scontext=3Dsystem_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:bin_t:s0 tclass=3Dfile With systems where many denials are occurring, it is useful to apply a filter. The filtering is a set of logic that is inserted with the filter file. Example: echo "tclass=3D=3D\"file\" " > events/avc/selinux_audited/filter This adds that we only get tclass=3Dfile. The trace can also have extra properties. Adding the user stack can be done with echo 1 > options/userstacktrace Now the output will be runcon-1365 [003] .... 6960.955530: selinux_audited: requested=3D0x4000000 denied=3D0x4000000 audited=3D0x4000000 result=3D-13 scontext=3Dsystem_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=3Dsystem_u:object_r:bin_t:s0 tclass=3Dfile runcon-1365 [003] .... 6960.955560: =3D> <00007f325b4ce45b> =3D> <00005607093efa57> Signed-off-by: Peter Enderborg Reviewed-by: Thi=C3=A9baud Weksteen --- include/trace/events/avc.h | 36 ++++++++++++++++++++++++++---------- security/selinux/avc.c | 22 +++++++++++++--------- 2 files changed, 39 insertions(+), 19 deletions(-) diff --git a/include/trace/events/avc.h b/include/trace/events/avc.h index 07c058a9bbcd..b55fda2e0773 100644 --- a/include/trace/events/avc.h +++ b/include/trace/events/avc.h @@ -1,6 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* - * Author: Thi=C3=A9baud Weksteen + * Authors: Thi=C3=A9baud Weksteen + * Peter Enderborg */ #undef TRACE_SYSTEM #define TRACE_SYSTEM avc @@ -12,23 +13,38 @@ =20 TRACE_EVENT(selinux_audited, =20 - TP_PROTO(struct selinux_audit_data *sad), + TP_PROTO(struct selinux_audit_data *sad, + char *scontext, + char *tcontext, + const char *tclass + ), =20 - TP_ARGS(sad), + TP_ARGS(sad, scontext, tcontext, tclass), =20 TP_STRUCT__entry( - __field(unsigned int, tclass) - __field(unsigned int, audited) + __field(u32, requested) + __field(u32, denied) + __field(u32, audited) + __field(int, result) + __string(scontext, scontext) + __string(tcontext, tcontext) + __string(tclass, tclass) ), =20 TP_fast_assign( - __entry->tclass =3D sad->tclass; - __entry->audited =3D sad->audited; + __entry->requested =3D sad->requested; + __entry->denied =3D sad->denied; + __entry->audited =3D sad->audited; + __entry->result =3D sad->result; + __assign_str(tcontext, tcontext); + __assign_str(scontext, scontext); + __assign_str(tclass, tclass); ), =20 - TP_printk("tclass=3D%u audited=3D%x", - __entry->tclass, - __entry->audited) + TP_printk("requested=3D0x%x denied=3D0x%x audited=3D0x%x result=3D%d scon= text=3D%s tcontext=3D%s tclass=3D%s", + __entry->requested, __entry->denied, __entry->audited, __entry->result, + __get_str(scontext), __get_str(tcontext), __get_str(tclass) + ) ); =20 #endif diff --git a/security/selinux/avc.c b/security/selinux/avc.c index b0a0af778b70..7de5cc5169af 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -705,35 +705,39 @@ static void avc_audit_post_callback(struct audit_buff= er *ab, void *a) { struct common_audit_data *ad =3D a; struct selinux_audit_data *sad =3D ad->selinux_audit_data; - char *scontext; + char *scontext =3D NULL; + char *tcontext =3D NULL; + const char *tclass =3D NULL; u32 scontext_len; + u32 tcontext_len; int rc; =20 - trace_selinux_audited(sad); - rc =3D security_sid_to_context(sad->state, sad->ssid, &scontext, &scontext_len); if (rc) audit_log_format(ab, " ssid=3D%d", sad->ssid); else { audit_log_format(ab, " scontext=3D%s", scontext); - kfree(scontext); } =20 - rc =3D security_sid_to_context(sad->state, sad->tsid, &scontext, - &scontext_len); + rc =3D security_sid_to_context(sad->state, sad->tsid, &tcontext, + &tcontext_len); if (rc) audit_log_format(ab, " tsid=3D%d", sad->tsid); else { - audit_log_format(ab, " tcontext=3D%s", scontext); - kfree(scontext); + audit_log_format(ab, " tcontext=3D%s", tcontext); } =20 - audit_log_format(ab, " tclass=3D%s", secclass_map[sad->tclass-1].name); + tclass =3D secclass_map[sad->tclass-1].name; + audit_log_format(ab, " tclass=3D%s", tclass); =20 if (sad->denied) audit_log_format(ab, " permissive=3D%u", sad->result ? 0 : 1); =20 + trace_selinux_audited(sad, scontext, tcontext, tclass); + kfree(tcontext); + kfree(scontext); + /* in case of invalid context report also the actual context string */ rc =3D security_sid_to_context_inval(sad->state, sad->ssid, &scontext, &scontext_len); --=20 2.28.0.220.ged08abb693-goog