| From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 029/164] ARM: 8426/1: dma-mapping: add missing range check in dma_mmap() | Date | Wed, 2 Dec 2015 08:58:00 -0800 |
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3.19.8-ckt11 -stable review patch. If anyone has any objections, please let me know.
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From: Marek Szyprowski <m.szyprowski@samsung.com>
commit 371f0f085f629fc0f66695f572373ca4445a67ad upstream.
dma_mmap() function in IOMMU-based dma-mapping implementation lacked a check for valid range of mmap parameters (offset and buffer size), what might have caused access beyond the allocated buffer. This patch fixes this issue.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/arm/mm/dma-mapping.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index bc074ef..30558bb 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1365,12 +1365,17 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, unsigned long uaddr = vma->vm_start; unsigned long usize = vma->vm_end - vma->vm_start; struct page **pages = __iommu_get_pages(cpu_addr, attrs); + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long off = vma->vm_pgoff; vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); if (!pages) return -ENXIO; + if (off >= nr_pages || (usize >> PAGE_SHIFT) > nr_pages - off) + return -ENXIO; + do { int ret = vm_insert_page(vma, uaddr, *pages++); if (ret) { -- 1.9.1
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