From 6b0c54e7f2715997c366e8374209bc74259b0a59 Mon Sep 17 00:00:00 2001 From: Yunsheng Lin Date: Sat, 24 Aug 2019 09:47:12 +0800 Subject: iommu/dma: Fix for dereferencing before null checking The cookie is dereferenced before null checking in the function iommu_dma_init_domain. This patch moves the dereferencing after the null checking. Fixes: fdbe574eb693 ("iommu/dma: Allow MSI-only cookies") Signed-off-by: Yunsheng Lin Signed-off-by: Joerg Roedel --- drivers/iommu/dma-iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/iommu/dma-iommu.c') diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 80beb1f5994a..8ce9db9c2cf6 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -303,13 +303,15 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size, struct device *dev) { struct iommu_dma_cookie *cookie = domain->iova_cookie; - struct iova_domain *iovad = &cookie->iovad; unsigned long order, base_pfn; + struct iova_domain *iovad; int attr; if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) return -EINVAL; + iovad = &cookie->iovad; + /* Use the smallest supported page size for IOVA granularity */ order = __ffs(domain->pgsize_bitmap); base_pfn = max_t(unsigned long, 1, base >> order); -- cgit v1.2.3