Messages in this thread Patch in this message | | | From | Christoph Hellwig <> | Subject | [PATCH 02/21] arm64/iommu: improve mmap bounds checking | Date | Wed, 27 Mar 2019 09:04:29 +0100 |
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The nr_pages checks should be done for all mmap requests, not just those using remap_pfn_range.
Signed-off-by: Christoph Hellwig <hch@lst.de> --- 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 be88beb2e377..e54288921e72 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); -- 2.20.1
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