From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753611AbdLGRiY (ORCPT ); Thu, 7 Dec 2017 12:38:24 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:60877 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755655AbdLGPtq (ORCPT ); Thu, 7 Dec 2017 10:49:46 -0500 From: alexander.levin@verizon.com Cc: Oleksandr Tyshchenko , Will Deacon , Robin Murphy , alexander.levin@verizon.com X-Host: pioneer.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.9 018/156] iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it Thread-Topic: [PATCH AUTOSEL for 4.9 018/156] iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it Thread-Index: AQHTb3LlhOYU8kmD60CPJgRMXhTAKA== Date: Thu, 7 Dec 2017 15:48:58 +0000 Message-ID: <20171207154845.4814-18-alexander.levin@verizon.com> References: <20171207154845.4814-1-alexander.levin@verizon.com> In-Reply-To: <20171207154845.4814-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7HcjwG032442 From: Oleksandr Tyshchenko [ Upstream commit a03849e7210277fa212779b7cd9c30e1ab6194b2 ] Do a check for already installed leaf entry at the current level before dereferencing it in order to avoid walking the page table down with wrong pointer to the next level. Signed-off-by: Oleksandr Tyshchenko CC: Will Deacon CC: Robin Murphy Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index f50e51c1a9c8..d68a552cfe8d 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -418,8 +418,12 @@ static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, pte |= ARM_V7S_ATTR_NS_TABLE; __arm_v7s_set_pte(ptep, pte, 1, cfg); - } else { + } else if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { cptep = iopte_deref(pte, lvl); + } else { + /* We require an unmap first */ + WARN_ON(!selftest_running); + return -EEXIST; } /* Rinse, repeat */ -- 2.11.0