From patchwork Tue Jun 19 12:52:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 10474289 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2F67B601D7 for ; Tue, 19 Jun 2018 12:59:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2153F28B0C for ; Tue, 19 Jun 2018 12:59:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 15F1C28B9A; Tue, 19 Jun 2018 12:59:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9707228B0C for ; Tue, 19 Jun 2018 12:59:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=HHCjrNrPS0hXGLyTC9prEOry8d/8I5nd9bjeRxmazxs=; b=gGr DoFESGKDAofFsgahOMT8K5jmZ9lDwfRvk7/vvKxQXDMccLcZxRvrySWcT+OV0kJqKRPC58x2uPE4z 38mq0MO+GxZLUMQPMlble0QdaBEYCVG30g4tLql436PFzJcX7nib46IfeV/45fxWVuryMRqq8lVea WxZzg0opvLpjOuB21FIBYYp6n2+tE29mghKlRCgGrK6alkgwLnB0VdDBRtZ4WKH5RJNKz41nS4J5T GIZhrW9QWlhyBz6TBX7ojX6UcMIi7OwmOV5ryrhg1JfpwEeJ6CMy8RenS4FTBiDSCHkYIsLYK8I3T KDvREUMPtsJaBb5A+hrcoHwPWYiNB5g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fVGEd-0008Cm-DB; Tue, 19 Jun 2018 12:59:47 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fVG8Z-0003pQ-NW for linux-arm-kernel@lists.infradead.org; Tue, 19 Jun 2018 12:54:33 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C98BD80D; Tue, 19 Jun 2018 05:53:19 -0700 (PDT) Received: from ostrya.cambridge.arm.com (ostrya.cambridge.arm.com [10.1.210.39]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BBE7D3F557; Tue, 19 Jun 2018 05:53:18 -0700 (PDT) From: Jean-Philippe Brucker To: iommu@lists.linux-foundation.org Subject: [PATCH] iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE Date: Tue, 19 Jun 2018 13:52:24 +0100 Message-Id: <20180619125224.1008-1-jean-philippe.brucker@arm.com> X-Mailer: git-send-email 2.17.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180619_055331_794567_FEE924B6 X-CRM114-Status: GOOD ( 13.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: will.deacon@arm.com, joro@8bytes.org, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When run on a 64-bit system in selftest, the v7s driver may obtain page table with physical addresses larger than 32-bit. Level-2 tables are 1KB and are are allocated with slab, which doesn't accept the GFP_DMA32 flag. Currently map() truncates the address written in the PTE, causing iova_to_phys() or unmap() to access invalid memory. Kasan reports it as a use-after-free. To avoid any nasty surprise, test if the physical address fits in a PTE before returning a new table. 32-bit systems, which are the main users of this page table format, shouldn't see any difference. Signed-off-by: Jean-Philippe Brucker --- drivers/iommu/io-pgtable-arm-v7s.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index 50e3a9fcf43e..b5948ba6b3b3 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -192,6 +192,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, { struct io_pgtable_cfg *cfg = &data->iop.cfg; struct device *dev = cfg->iommu_dev; + phys_addr_t phys; dma_addr_t dma; size_t size = ARM_V7S_TABLE_SIZE(lvl); void *table = NULL; @@ -200,6 +201,10 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size)); else if (lvl == 2) table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA); + phys = virt_to_phys(table); + if (phys != (arm_v7s_iopte)phys) + /* Doesn't fit in PTE */ + goto out_free; if (table && !(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) { dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); if (dma_mapping_error(dev, dma)) @@ -209,7 +214,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, * address directly, so if the DMA layer suggests otherwise by * translating or truncating them, that bodes very badly... */ - if (dma != virt_to_phys(table)) + if (dma != phys) goto out_unmap; } kmemleak_ignore(table);