From patchwork Sun Mar 4 11:55:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: maddy X-Patchwork-Id: 881161 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3zvM473PgYz9s7C for ; Sun, 4 Mar 2018 22:57:59 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.vnet.ibm.com Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3zvM470Ss0zDsND for ; Sun, 4 Mar 2018 22:57:59 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.vnet.ibm.com X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=maddy@linux.vnet.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.vnet.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zvM1S72lZzF09H for ; Sun, 4 Mar 2018 22:55:37 +1100 (AEDT) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w24BrrvK035983 for ; Sun, 4 Mar 2018 06:55:34 -0500 Received: from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109]) by mx0a-001b2d01.pphosted.com with ESMTP id 2gg9j1hjxw-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Sun, 04 Mar 2018 06:55:34 -0500 Received: from localhost by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Sun, 4 Mar 2018 11:55:31 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w24BtVeU51707960; Sun, 4 Mar 2018 11:55:31 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5CFEC4C044; Sun, 4 Mar 2018 11:48:56 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6AD084C040; Sun, 4 Mar 2018 11:48:55 +0000 (GMT) Received: from SrihariSrinidhi.in.ibm.com (unknown [9.79.193.254]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Sun, 4 Mar 2018 11:48:55 +0000 (GMT) From: Madhavan Srinivasan To: mpe@ellerman.id.au Subject: [PATCH 1/2] powerpc/perf: Fix kernel address leak to userspace via BHRB buffer Date: Sun, 4 Mar 2018 17:25:17 +0530 X-Mailer: git-send-email 2.7.4 X-TM-AS-GCONF: 00 x-cbid: 18030411-0012-0000-0000-000005B8860F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18030411-0013-0000-0000-00001934943D Message-Id: <1520164518-19097-1-git-send-email-maddy@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-03-04_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803040155 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Madhavan Srinivasan , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The current Branch History Rolling Buffer (BHRB) code does not check for any privilege levels before updating the data from BHRB. This leaks kernel addresses to userspace even when profiling only with userspace privileges. Add proper checks to prevent it. Signed-off-by: Madhavan Srinivasan Acked-by: Balbir Singh --- arch/powerpc/perf/core-book3s.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index f89bbd54ecec..337db5831749 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -457,6 +457,10 @@ static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) /* invalid entry */ continue; + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) && + is_kernel_addr(addr)) + continue; + /* Branches are read most recent first (ie. mfbhrb 0 is * the most recent branch). * There are two types of valid entries: