From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933772AbcIONgv (ORCPT ); Thu, 15 Sep 2016 09:36:51 -0400 Received: from mga11.intel.com ([192.55.52.93]:65374 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754265AbcIONge (ORCPT ); Thu, 15 Sep 2016 09:36:34 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,339,1470726000"; d="scan'208";a="1030565451" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, vince@deater.net, eranian@google.com, Arnaldo Carvalho de Melo , Alexander Shishkin , stable@vger.kernel.org#4.7 Subject: [PATCH 3/3] perf/x86/intel/pt: Do validate the size of a kernel address filter Date: Thu, 15 Sep 2016 16:29:44 +0300 Message-Id: <20160915132944.10331-4-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160915132944.10331-1-alexander.shishkin@linux.intel.com> References: <20160915132944.10331-1-alexander.shishkin@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Right now, the kernel address filters in PT are prone to integer overflow that may happen in adding filter's size to its offset to obtain the end of the range. Such an overflow would also throw a #GP in the PT event configuration path. Fix this by explicitly validating the result of this calculation. Cc: stable@vger.kernel.org # 4.7 Reported-by: Adrian Hunter Signed-off-by: Alexander Shishkin --- arch/x86/events/intel/pt.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 5ec0100e3f..834ce06b00 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1084,8 +1084,13 @@ static int pt_event_addr_filters_validate(struct list_head *filters) if (!filter->range || !filter->size) return -EOPNOTSUPP; - if (!filter->inode && !kernel_ip(filter->offset)) - return -EINVAL; + if (!filter->inode) { + if (!kernel_ip(filter->offset)) + return -EINVAL; + + if (!kernel_ip(filter->offset + filter->size)) + return -EINVAL; + } if (++range > pt_cap_get(PT_CAP_num_address_ranges)) return -EOPNOTSUPP; -- 2.9.3