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[23.128.96.18]) by mx.google.com with ESMTP id y16si1291170edc.193.2021.06.02.18.52.07; Wed, 02 Jun 2021 18:52:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=ksjTJUw8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229769AbhFCBvm (ORCPT + 99 others); Wed, 2 Jun 2021 21:51:42 -0400 Received: from mail-qv1-f48.google.com ([209.85.219.48]:39458 "EHLO mail-qv1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229685AbhFCBvl (ORCPT ); Wed, 2 Jun 2021 21:51:41 -0400 Received: by mail-qv1-f48.google.com with SMTP id eb9so2444325qvb.6 for ; Wed, 02 Jun 2021 18:49:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=A5jFSAkEfzoPDzF2tYC9gryznUBk4WFIWwyTkqnypAk=; b=ksjTJUw8+GzcoidJIpun6CtJWtzTauUj+atJzClf1nhOD8Yi1OYY125VnQlDIefkYW lUynAheYsqtUMtBz0g1D/PuCKmsJlwHgUaYq/ZWpkyl6nGJrEyMLtTMVH3tmps5Wrv57 yXY8ld5kvbVCT3qO2FLnppjbn8Ms6Yha9kknZRlLTKE0VngOxvLhmIs6tqiaNspwAifb ufy8cS07Rt+lb/kJucK75Ky83XOH/ZCIyXaaWTwpwD43Usi66/Io3uKpTYXt7axAMW9e eJk6qIkgbTg9ZgtMa58E0WuZl4PCyJHDOlF3zcZgsgq5Et7c9oV8ThnD7b8NtQn9Wfbe A8oA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=A5jFSAkEfzoPDzF2tYC9gryznUBk4WFIWwyTkqnypAk=; b=r0dpsRV+cZQjUCnDfREiwU7xVvLzYJ38CdYbOyWVPsYeRN5mUArqexIGaz7bTjQ8Wu hU3k0u1m4QezYD24T0bcTKAtCZ+L2uWCSLZyoEkfFC5BgGnOUtOoG7/UUq7V8g3XQzeK 6cnD38XH6Mz1XeQIje/91jeWdmG21KUGNKsJnZCyjpHXbmncBh3dnS4Uc0ocYYf8bZ5L NVKFgDdc6XmZ/cNAQTxZ1+cDtnm3WejS35Ko3fVaTGF7cA+OfVopwuYd1M17yk8QnV7u T5jZ+JF0p90ZIx8eJnGI+i5CazQ6McjkAO/dlDp5Vn75aRN6MydrpSss+FXlCGDp3OKw TkRA== X-Gm-Message-State: AOAM5330YqQQAwzbzgMiAOSQFew2RPzQkyYdpv/fBcDH6xMREBgdLl9Y koDDwNcY2NyX+st9pF2kSCU0XjAeRYU= X-Received: by 2002:a0c:83e1:: with SMTP id k88mr31613572qva.40.1622684922286; Wed, 02 Jun 2021 18:48:42 -0700 (PDT) Received: from localhost.localdomain ([130.44.160.152]) by smtp.gmail.com with ESMTPSA id h62sm1045259qkf.45.2021.06.02.18.48.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Jun 2021 18:48:41 -0700 (PDT) Sender: Konrad Rzeszutek Wilk Date: Wed, 2 Jun 2021 21:48:39 -0400 From: Konrad Rzeszutek Wilk To: Andi Kleen Cc: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, iommu@lists.linux-foundation.org, x86@kernel.org, sathyanarayanan.kuppuswamy@linux.intel.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 5/8] dma: Use size for swiotlb boundary checks Message-ID: References: <20210603004133.4079390-1-ak@linux.intel.com> <20210603004133.4079390-6-ak@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210603004133.4079390-6-ak@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 02, 2021 at 05:41:30PM -0700, Andi Kleen wrote: > swiotlb currently only uses the start address of a DMA to check if something > is in the swiotlb or not. But with virtio and untrusted hosts the host > could give some DMA mapping that crosses the swiotlb boundaries, > potentially leaking or corrupting data. Add size checks to all the swiotlb > checks and reject any DMAs that cross the swiotlb buffer boundaries. I seem to be only CC-ed on this and #7, so please bear with me. But could you explain to me why please: commit daf9514fd5eb098d7d6f3a1247cb8cc48fc94155 (swiotlb/stable/for-linus-5.12) Author: Martin Radev Date: Tue Jan 12 16:07:29 2021 +0100 swiotlb: Validate bounce size in the sync/unmap path does not solve the problem as well? > > Signed-off-by: Andi Kleen > --- > drivers/iommu/dma-iommu.c | 13 ++++++------- > drivers/xen/swiotlb-xen.c | 11 ++++++----- > include/linux/dma-mapping.h | 4 ++-- > include/linux/swiotlb.h | 8 +++++--- > kernel/dma/direct.c | 8 ++++---- > kernel/dma/direct.h | 8 ++++---- > kernel/dma/mapping.c | 4 ++-- > net/xdp/xsk_buff_pool.c | 2 +- > 8 files changed, 30 insertions(+), 28 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 7bcdd1205535..7ef13198721b 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -504,7 +504,7 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr, > > __iommu_dma_unmap(dev, dma_addr, size); > > - if (unlikely(is_swiotlb_buffer(phys))) > + if (unlikely(is_swiotlb_buffer(phys, size))) > swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); > } > > @@ -575,7 +575,7 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, > } > > iova = __iommu_dma_map(dev, phys, aligned_size, prot, dma_mask); > - if (iova == DMA_MAPPING_ERROR && is_swiotlb_buffer(phys)) > + if (iova == DMA_MAPPING_ERROR && is_swiotlb_buffer(phys, org_size)) > swiotlb_tbl_unmap_single(dev, phys, org_size, dir, attrs); > return iova; > } > @@ -781,7 +781,7 @@ static void iommu_dma_sync_single_for_cpu(struct device *dev, > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_cpu(phys, size, dir); > > - if (is_swiotlb_buffer(phys)) > + if (is_swiotlb_buffer(phys, size)) > swiotlb_sync_single_for_cpu(dev, phys, size, dir); > } > > @@ -794,7 +794,7 @@ static void iommu_dma_sync_single_for_device(struct device *dev, > return; > > phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle); > - if (is_swiotlb_buffer(phys)) > + if (is_swiotlb_buffer(phys, size)) > swiotlb_sync_single_for_device(dev, phys, size, dir); > > if (!dev_is_dma_coherent(dev)) > @@ -815,7 +815,7 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev, > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_cpu(sg_phys(sg), sg->length, dir); > > - if (is_swiotlb_buffer(sg_phys(sg))) > + if (is_swiotlb_buffer(sg_phys(sg), sg->length)) > swiotlb_sync_single_for_cpu(dev, sg_phys(sg), > sg->length, dir); > } > @@ -832,10 +832,9 @@ static void iommu_dma_sync_sg_for_device(struct device *dev, > return; > > for_each_sg(sgl, sg, nelems, i) { > - if (is_swiotlb_buffer(sg_phys(sg))) > + if (is_swiotlb_buffer(sg_phys(sg), sg->length)) > swiotlb_sync_single_for_device(dev, sg_phys(sg), > sg->length, dir); > - > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_device(sg_phys(sg), sg->length, dir); > } > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index 24d11861ac7d..333846af8d35 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -89,7 +89,8 @@ static inline int range_straddles_page_boundary(phys_addr_t p, size_t size) > return 0; > } > > -static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr) > +static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr, > + size_t size) > { > unsigned long bfn = XEN_PFN_DOWN(dma_to_phys(dev, dma_addr)); > unsigned long xen_pfn = bfn_to_local_pfn(bfn); > @@ -100,7 +101,7 @@ static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr) > * in our domain. Therefore _only_ check address within our domain. > */ > if (pfn_valid(PFN_DOWN(paddr))) > - return is_swiotlb_buffer(paddr); > + return is_swiotlb_buffer(paddr, size); > return 0; > } > > @@ -431,7 +432,7 @@ static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, > } > > /* NOTE: We use dev_addr here, not paddr! */ > - if (is_xen_swiotlb_buffer(hwdev, dev_addr)) > + if (is_xen_swiotlb_buffer(hwdev, dev_addr, size)) > swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs); > } > > @@ -448,7 +449,7 @@ xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr, > xen_dma_sync_for_cpu(dev, dma_addr, size, dir); > } > > - if (is_xen_swiotlb_buffer(dev, dma_addr)) > + if (is_xen_swiotlb_buffer(dev, dma_addr, size)) > swiotlb_sync_single_for_cpu(dev, paddr, size, dir); > } > > @@ -458,7 +459,7 @@ xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr, > { > phys_addr_t paddr = xen_dma_to_phys(dev, dma_addr); > > - if (is_xen_swiotlb_buffer(dev, dma_addr)) > + if (is_xen_swiotlb_buffer(dev, dma_addr, size)) > swiotlb_sync_single_for_device(dev, paddr, size, dir); > > if (!dev_is_dma_coherent(dev)) { > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 183e7103a66d..37fbd12bd4ab 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -142,7 +142,7 @@ int dma_set_mask(struct device *dev, u64 mask); > int dma_set_coherent_mask(struct device *dev, u64 mask); > u64 dma_get_required_mask(struct device *dev); > size_t dma_max_mapping_size(struct device *dev); > -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr); > +bool dma_need_sync(struct device *dev, dma_addr_t dma_addr, size_t size); > unsigned long dma_get_merge_boundary(struct device *dev); > struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size, > enum dma_data_direction dir, gfp_t gfp, unsigned long attrs); > @@ -258,7 +258,7 @@ static inline size_t dma_max_mapping_size(struct device *dev) > { > return 0; > } > -static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) > +static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr, size_t size) > { > return false; > } > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..3e447f722d81 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -101,11 +101,13 @@ struct io_tlb_mem { > }; > extern struct io_tlb_mem *io_tlb_default_mem; > > -static inline bool is_swiotlb_buffer(phys_addr_t paddr) > +static inline bool is_swiotlb_buffer(phys_addr_t paddr, size_t size) > { > struct io_tlb_mem *mem = io_tlb_default_mem; > > - return mem && paddr >= mem->start && paddr < mem->end; > + if (paddr + size <= paddr) /* wrapping */ > + return false; > + return mem && paddr >= mem->start && paddr + size <= mem->end; > } > > void __init swiotlb_exit(void); > @@ -115,7 +117,7 @@ bool is_swiotlb_active(void); > void __init swiotlb_adjust_size(unsigned long size); > #else > #define swiotlb_force SWIOTLB_NO_FORCE > -static inline bool is_swiotlb_buffer(phys_addr_t paddr) > +static inline bool is_swiotlb_buffer(phys_addr_t paddr, size_t size) > { > return false; > } > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index f737e3347059..9ae6f94e868f 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -343,7 +343,7 @@ void dma_direct_sync_sg_for_device(struct device *dev, > for_each_sg(sgl, sg, nents, i) { > phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg)); > > - if (unlikely(is_swiotlb_buffer(paddr))) > + if (unlikely(is_swiotlb_buffer(paddr, sg->length))) > swiotlb_sync_single_for_device(dev, paddr, sg->length, > dir); > > @@ -369,7 +369,7 @@ void dma_direct_sync_sg_for_cpu(struct device *dev, > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_cpu(paddr, sg->length, dir); > > - if (unlikely(is_swiotlb_buffer(paddr))) > + if (unlikely(is_swiotlb_buffer(paddr, sg->length))) > swiotlb_sync_single_for_cpu(dev, paddr, sg->length, > dir); > > @@ -501,10 +501,10 @@ size_t dma_direct_max_mapping_size(struct device *dev) > return SIZE_MAX; > } > > -bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr) > +bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr, size_t size) > { > return !dev_is_dma_coherent(dev) || > - is_swiotlb_buffer(dma_to_phys(dev, dma_addr)); > + is_swiotlb_buffer(dma_to_phys(dev, dma_addr), size); > } > > /** > diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h > index 50afc05b6f1d..4a17e431ae56 100644 > --- a/kernel/dma/direct.h > +++ b/kernel/dma/direct.h > @@ -16,7 +16,7 @@ bool dma_direct_can_mmap(struct device *dev); > int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs); > -bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr); > +bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr, size_t size); > int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > enum dma_data_direction dir, unsigned long attrs); > size_t dma_direct_max_mapping_size(struct device *dev); > @@ -56,7 +56,7 @@ static inline void dma_direct_sync_single_for_device(struct device *dev, > { > phys_addr_t paddr = dma_to_phys(dev, addr); > > - if (unlikely(is_swiotlb_buffer(paddr))) > + if (unlikely(is_swiotlb_buffer(paddr, size))) > swiotlb_sync_single_for_device(dev, paddr, size, dir); > > if (!dev_is_dma_coherent(dev)) > @@ -73,7 +73,7 @@ static inline void dma_direct_sync_single_for_cpu(struct device *dev, > arch_sync_dma_for_cpu_all(); > } > > - if (unlikely(is_swiotlb_buffer(paddr))) > + if (unlikely(is_swiotlb_buffer(paddr, size))) > swiotlb_sync_single_for_cpu(dev, paddr, size, dir); > > if (dir == DMA_FROM_DEVICE) > @@ -113,7 +113,7 @@ static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > dma_direct_sync_single_for_cpu(dev, addr, size, dir); > > - if (unlikely(is_swiotlb_buffer(phys))) > + if (unlikely(is_swiotlb_buffer(phys, size))) > swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); > } > #endif /* _KERNEL_DMA_DIRECT_H */ > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c > index 2b06a809d0b9..9bf02c8d7d1b 100644 > --- a/kernel/dma/mapping.c > +++ b/kernel/dma/mapping.c > @@ -716,12 +716,12 @@ size_t dma_max_mapping_size(struct device *dev) > } > EXPORT_SYMBOL_GPL(dma_max_mapping_size); > > -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) > +bool dma_need_sync(struct device *dev, dma_addr_t dma_addr, size_t size) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > if (dma_map_direct(dev, ops)) > - return dma_direct_need_sync(dev, dma_addr); > + return dma_direct_need_sync(dev, dma_addr, size); > return ops->sync_single_for_cpu || ops->sync_single_for_device; > } > EXPORT_SYMBOL_GPL(dma_need_sync); > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c > index 8de01aaac4a0..c1e404fe0cf4 100644 > --- a/net/xdp/xsk_buff_pool.c > +++ b/net/xdp/xsk_buff_pool.c > @@ -399,7 +399,7 @@ int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, > __xp_dma_unmap(dma_map, attrs); > return -ENOMEM; > } > - if (dma_need_sync(dev, dma)) > + if (dma_need_sync(dev, dma, PAGE_SIZE)) > dma_map->dma_need_sync = true; > dma_map->dma_pages[i] = dma; > } > -- > 2.25.4 >