From: Joerg Roedel Date: Wed, 27 May 2015 07:26:09 +0000 (+0200) Subject: iommu/amd: Handle integer overflow in dma_ops_area_alloc X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e6aabee05f41c9d18e0b92194819edd84f352ac9;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git iommu/amd: Handle integer overflow in dma_ops_area_alloc Handle this case to make sure boundary_size does not become 0 and trigger a BUG_ON later. Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index aa710b095f1a..4dfadcfed34a 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1699,14 +1699,16 @@ static unsigned long dma_ops_area_alloc(struct device *dev, unsigned long next_bit = dom->next_address % APERTURE_RANGE_SIZE; int max_index = dom->aperture_size >> APERTURE_RANGE_SHIFT; int i = start >> APERTURE_RANGE_SHIFT; - unsigned long boundary_size; + unsigned long boundary_size, mask; unsigned long address = -1; unsigned long limit; next_bit >>= PAGE_SHIFT; - boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - PAGE_SIZE) >> PAGE_SHIFT; + mask = dma_get_seg_boundary(dev); + + boundary_size = mask + 1 ? ALIGN(mask + 1, PAGE_SIZE) >> PAGE_SHIFT : + 1UL << (BITS_PER_LONG - PAGE_SHIFT); for (;i < max_index; ++i) { unsigned long offset = dom->aperture[i]->offset >> PAGE_SHIFT;