From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH 02/26] arm64/iommu: improve mmap bounds checking Date: Mon, 29 Apr 2019 13:35:46 +0100 Message-ID: <306b7a19-4eb5-d1d8-5250-40f3ba9bca16@arm.com> References: <20190422175942.18788-1-hch@lst.de> <20190422175942.18788-3-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190422175942.18788-3-hch@lst.de> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Christoph Hellwig Cc: Joerg Roedel , Catalin Marinas , Will Deacon , Tom Lendacky , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org On 22/04/2019 18:59, Christoph Hellwig wrote: > The nr_pages checks should be done for all mmap requests, not just those > using remap_pfn_range. I think it probably makes sense now to just squash this with #22 one way or the other, but if you really really still want to keep it as a separate patch with a misleading commit message then I'm willing to keep my complaints to myself :) Robin. > Signed-off-by: Christoph Hellwig > --- > arch/arm64/mm/dma-mapping.c | 21 ++++++++------------- > 1 file changed, 8 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index 674860e3e478..604c638b2787 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -73,19 +73,9 @@ static int __swiotlb_get_sgtable_page(struct sg_table *sgt, > static int __swiotlb_mmap_pfn(struct vm_area_struct *vma, > unsigned long pfn, size_t size) > { > - int ret = -ENXIO; > - unsigned long nr_vma_pages = vma_pages(vma); > - unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > - unsigned long off = vma->vm_pgoff; > - > - if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { > - ret = remap_pfn_range(vma, vma->vm_start, > - pfn + off, > - vma->vm_end - vma->vm_start, > - vma->vm_page_prot); > - } > - > - return ret; > + return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, > + vma->vm_end - vma->vm_start, > + vma->vm_page_prot); > } > #endif /* CONFIG_IOMMU_DMA */ > > @@ -241,6 +231,8 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > + unsigned long off = vma->vm_pgoff; > struct vm_struct *area; > int ret; > > @@ -249,6 +241,9 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) > return ret; > > + if (off >= nr_pages || vma_pages(vma) > nr_pages - off) > + return -ENXIO; > + > if (!is_vmalloc_addr(cpu_addr)) { > unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr)); > return __swiotlb_mmap_pfn(vma, pfn, size); > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68B20C43219 for ; Mon, 29 Apr 2019 12:38:17 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 38CE320675 for ; Mon, 29 Apr 2019 12:38:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38CE320675 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id E9F9F2110; Mon, 29 Apr 2019 12:38:16 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id B3AB22106 for ; Mon, 29 Apr 2019 12:35:49 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 5B4FF711 for ; Mon, 29 Apr 2019 12:35:49 +0000 (UTC) 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 E9212A78; Mon, 29 Apr 2019 05:35:48 -0700 (PDT) Received: from [10.1.196.75] (e110467-lin.cambridge.arm.com [10.1.196.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 826383F740; Mon, 29 Apr 2019 05:35:47 -0700 (PDT) Subject: Re: [PATCH 02/26] arm64/iommu: improve mmap bounds checking To: Christoph Hellwig References: <20190422175942.18788-1-hch@lst.de> <20190422175942.18788-3-hch@lst.de> From: Robin Murphy Message-ID: <306b7a19-4eb5-d1d8-5250-40f3ba9bca16@arm.com> Date: Mon, 29 Apr 2019 13:35:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190422175942.18788-3-hch@lst.de> Content-Language: en-GB Cc: Tom Lendacky , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="UTF-8"; format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190429123546.7mrNis14Bfd2iIkWjHw4nEbun_Rji4IvY2651MEnj1Y@z> On 22/04/2019 18:59, Christoph Hellwig wrote: > The nr_pages checks should be done for all mmap requests, not just those > using remap_pfn_range. I think it probably makes sense now to just squash this with #22 one way or the other, but if you really really still want to keep it as a separate patch with a misleading commit message then I'm willing to keep my complaints to myself :) Robin. > Signed-off-by: Christoph Hellwig > --- > arch/arm64/mm/dma-mapping.c | 21 ++++++++------------- > 1 file changed, 8 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index 674860e3e478..604c638b2787 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -73,19 +73,9 @@ static int __swiotlb_get_sgtable_page(struct sg_table *sgt, > static int __swiotlb_mmap_pfn(struct vm_area_struct *vma, > unsigned long pfn, size_t size) > { > - int ret = -ENXIO; > - unsigned long nr_vma_pages = vma_pages(vma); > - unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > - unsigned long off = vma->vm_pgoff; > - > - if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { > - ret = remap_pfn_range(vma, vma->vm_start, > - pfn + off, > - vma->vm_end - vma->vm_start, > - vma->vm_page_prot); > - } > - > - return ret; > + return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, > + vma->vm_end - vma->vm_start, > + vma->vm_page_prot); > } > #endif /* CONFIG_IOMMU_DMA */ > > @@ -241,6 +231,8 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > + unsigned long off = vma->vm_pgoff; > struct vm_struct *area; > int ret; > > @@ -249,6 +241,9 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) > return ret; > > + if (off >= nr_pages || vma_pages(vma) > nr_pages - off) > + return -ENXIO; > + > if (!is_vmalloc_addr(cpu_addr)) { > unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr)); > return __swiotlb_mmap_pfn(vma, pfn, size); > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu