From patchwork Fri Jul 24 09:15:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thi=C3=A9baud_Weksteen?= X-Patchwork-Id: 11682797 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 75D0A912 for ; Fri, 24 Jul 2020 09:15:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C3A2206EB for ; Fri, 24 Jul 2020 09:15:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="R+rUbDNs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727098AbgGXJPp (ORCPT ); Fri, 24 Jul 2020 05:15:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726861AbgGXJPo (ORCPT ); Fri, 24 Jul 2020 05:15:44 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFB38C0619E4 for ; Fri, 24 Jul 2020 02:15:44 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id w35so9700219ybi.16 for ; Fri, 24 Jul 2020 02:15:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc :content-transfer-encoding; bh=igO9PGS75sNuJ8Wtx045r3V9fh7O7ARU1wRPKhhhbQE=; b=R+rUbDNs7Bx8jqcdI/0YnjROZGc4JO11o3nTpLn5lsj9M24wu/7TLUpdRlFQsdGfCa 6h8fwusAeBgzGxpmkfcbnTF8ArO9m1/wwq8SJ52rtE4kbBKp0UB0GhxYoINnPgvXBPio Xbl6/B7Roex2OG0din1MoSF8GcXY2ufWoCWrOJy8Ilhr9xM+ymkn4Qe8CoqsnZ2Q6LCb 0uLmPj0Hkq0xoCiU9GSmZoP+E8EizD92Yu7oYgDE+VbNfMObA6Jz2pF10TBEJ8iLaW0Y Pfcx8bnuvf0qigg9i+8Rm39+1xqJRhKfD0LVwRMWZRXtYLzd+TVKnPKrG/TVJmoZzZL/ tSdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc :content-transfer-encoding; bh=igO9PGS75sNuJ8Wtx045r3V9fh7O7ARU1wRPKhhhbQE=; b=c7raE2vZri10JTI1qGQO/BqFWpkkEBIrczCid9EhId51XJ+61togQRo5Qewxn5gNe+ pfbDMfHbuFvccVzOxCO00r20fofQpda9KtUgA0sAO0u7iekF3LRb6XocVmcM+uniZRty TcRNwAq/JFFAPgsM7rXNv3VCLKllPkG9J4nBgKTRyadqQ/YJy83OVJc8NdiBKUJ/3beR yCcc1cCJT7DT6+nIeqWEM6b22kgKEqE+A4C2IEUB/p9jLokdnMrnjTVqWAhw9GSppWT5 YaKYu3pGHOZ4AmadbaenV+svJNVVvNt3eXU1+ulCucD6UCWs5xB8omco/pt919VEsLDW aWqw== X-Gm-Message-State: AOAM531pYeotRIiYYpA4AQgH+9QG0Tn/eusaCza/xNvs8EYUqbOsK9vB yjawJuEYrX5Hkrh/4xOsW26/XfOm3Q== X-Google-Smtp-Source: ABdhPJxBSbg2aspYRo4mU3t74skGgXHjg4D4uwizYyZEnFxQ3NDgIaIEeQc0fTaUkekLPb35WUE5II5lwg== X-Received: by 2002:a5b:449:: with SMTP id s9mr2280682ybp.465.1595582143955; Fri, 24 Jul 2020 02:15:43 -0700 (PDT) Date: Fri, 24 Jul 2020 11:15:03 +0200 Message-Id: <20200724091520.880211-1-tweek@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.rc0.142.g3c755180ce-goog Subject: [PATCH] selinux: add tracepoint on denials From: " =?utf-8?q?Thi=C3=A9baud_Weksteen?= " To: Paul Moore Cc: Nick Kralevich , " =?utf-8?q?Thi=C3=A9baud_Weksteen?= " , Joel Fernandes , 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 Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org The audit data currently captures which process and which target is responsible for a denial. There is no data on where exactly in the process that call occurred. Debugging can be made easier by being able to reconstruct the unified kernel and userland stack traces [1]. Add a tracepoint on the SELinux denials which can then be used by userland (i.e. perf). Although this patch could manually be added by each OS developer to trouble shoot a denial, adding it to the kernel streamlines the developers workflow. [1] https://source.android.com/devices/tech/debug/native_stack_dump Signed-off-by: Thiébaud Weksteen Signed-off-by: Joel Fernandes --- MAINTAINERS | 1 + include/trace/events/selinux.h | 35 ++++++++++++++++++++++++++++++++++ security/selinux/avc.c | 6 ++++++ 3 files changed, 42 insertions(+) create mode 100644 include/trace/events/selinux.h diff --git a/MAINTAINERS b/MAINTAINERS index e64cdde81851..6b6cd5e13537 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15358,6 +15358,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git F: Documentation/ABI/obsolete/sysfs-selinux-checkreqprot F: Documentation/ABI/obsolete/sysfs-selinux-disable F: Documentation/admin-guide/LSM/SELinux.rst +F: include/trace/events/selinux.h F: include/uapi/linux/selinux_netlink.h F: scripts/selinux/ F: security/selinux/ diff --git a/include/trace/events/selinux.h b/include/trace/events/selinux.h new file mode 100644 index 000000000000..e247187a8135 --- /dev/null +++ b/include/trace/events/selinux.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM selinux + +#if !defined(_TRACE_SELINUX_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_SELINUX_H + +#include +#include + +TRACE_EVENT(selinux_denied, + + TP_PROTO(int cls, int av), + + TP_ARGS(cls, av), + + TP_STRUCT__entry( + __field(int, cls) + __field(int, av) + ), + + TP_fast_assign( + __entry->cls = cls; + __entry->av = av; + ), + + TP_printk("denied %d %d", + __entry->cls, + __entry->av) +); + +#endif + +/* This part must be outside protection */ +#include diff --git a/security/selinux/avc.c b/security/selinux/avc.c index d18cb32a242a..85d2e22ab656 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -31,6 +31,9 @@ #include "avc_ss.h" #include "classmap.h" +#define CREATE_TRACE_POINTS +#include + #define AVC_CACHE_SLOTS 512 #define AVC_DEF_CACHE_THRESHOLD 512 #define AVC_CACHE_RECLAIM 16 @@ -672,6 +675,9 @@ static void avc_audit_pre_callback(struct audit_buffer *ab, void *a) return; } + if (sad->denied) + trace_selinux_denied(sad->tclass, av); + perms = secclass_map[sad->tclass-1].perms; audit_log_format(ab, " {");