From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935142AbdLRQBT (ORCPT ); Mon, 18 Dec 2017 11:01:19 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:38014 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935123AbdLRQBJ (ORCPT ); Mon, 18 Dec 2017 11:01:09 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleksandr Tyshchenko , Will Deacon , Robin Murphy , Sasha Levin Subject: [PATCH 4.9 041/177] iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it Date: Mon, 18 Dec 2017 16:47:44 +0100 Message-Id: <20171218152912.049343764@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171218152909.823644066@linuxfoundation.org> References: <20171218152909.823644066@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- 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_ 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 */