lkml.org 
[lkml]   [2019]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 02/21] arm64/iommu: improve mmap bounds checking
    Date
    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
    \
     
     \ /
      Last update: 2019-03-27 09:05    [W:3.706 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site