From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbdJFIzi (ORCPT ); Fri, 6 Oct 2017 04:55:38 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49618 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752225AbdJFIzg (ORCPT ); Fri, 6 Oct 2017 04:55:36 -0400 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 4.9 085/104] iommu/io-pgtable-arm: Check for leaf entry before dereferencing it Date: Fri, 6 Oct 2017 10:52:03 +0200 Message-Id: <20171006083853.469676867@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171006083840.743659740@linuxfoundation.org> References: <20171006083840.743659740@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 ed46e66cc1b3d684042f92dfa2ab15ee917b4cac ] 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.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -335,8 +335,12 @@ static int __arm_lpae_map(struct arm_lpa if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) pte |= ARM_LPAE_PTE_NSTABLE; __arm_lpae_set_pte(ptep, pte, cfg); - } else { + } else if (!iopte_leaf(pte, lvl)) { cptep = iopte_deref(pte, data); + } else { + /* We require an unmap first */ + WARN_ON(!selftest_running); + return -EEXIST; } /* Rinse, repeat */