From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754356AbbH0POU (ORCPT ); Thu, 27 Aug 2015 11:14:20 -0400 Received: from mga03.intel.com ([134.134.136.65]:46787 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752668AbbH0POT (ORCPT ); Thu, 27 Aug 2015 11:14:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,422,1437462000"; d="scan'208";a="776806935" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Alexander Shishkin Subject: [PATCH 0/2] perf/x86/intel: Work around BTS leaking kernel addresses Date: Thu, 27 Aug 2015 18:13:40 +0300 Message-Id: <1440688422-27954-1-git-send-email-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.5.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, Due to imprecise IP sampling, BTS may (and often does) leak kernel addresses when kernel tracing is not even enabled, which results in mostly syscall entry points and page_fault handler addresses being exposed. This might be a security concern for the address randomization, and it also makes life harder for gdb that makes use of bts samples. This patchset works around the old (DS) driver and disables the new (intel_bts) for the unprivileged users on systems where perf paranoia level prohibits kernel tracing. Not sure if these should be treated as bugfixes. Alexander Shishkin (2): perf/x86/intel/ds: Work around BTS leaking kernel addresses perf/x86/intel/bts: Disallow use by unprivileged users on paranoid systems arch/x86/kernel/cpu/perf_event_intel_bts.c | 10 ++++++++ arch/x86/kernel/cpu/perf_event_intel_ds.c | 40 +++++++++++++++++++++++++----- 2 files changed, 44 insertions(+), 6 deletions(-) -- 2.5.0