From: Marek Szyprowski Date: Wed, 1 Jul 2015 12:43:54 +0000 (+0200) Subject: arm: dma-mapping: fix off-by-one error in bitmap size check X-Git-Tag: submit/tizen/20160405.082219~95 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f0d3c8693af61f7274f328520800b50cd04b65b0;p=platform%2Fkernel%2Flinux-exynos.git arm: dma-mapping: fix off-by-one error in bitmap size check nr_bitmaps member of mapping structure stores the number of already allocated bitmaps and it is interpreted as loop iterator (it starts from 0 not from 1), so a comparison against number of possible bitmap extensions should include this fact. This patch fixes this by changing the extension failure condition. This issue has been introduced by commit 4d852ef8c2544ce21ae41414099a7504c61164a0 ("arm: dma-mapping: Add support to extend DMA IOMMU mappings"). Reported-by: Hyungwon Hwang Signed-off-by: Marek Szyprowski CC: stable@vger.kernel.org # v3.15+ --- diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 423cb9f8ab0d..3b11d23c6749 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1997,7 +1997,7 @@ static int extend_iommu_mapping(struct dma_iommu_mapping *mapping) { int next_bitmap; - if (mapping->nr_bitmaps > mapping->extensions) + if (mapping->nr_bitmaps >= mapping->extensions) return -EINVAL; next_bitmap = mapping->nr_bitmaps;