From ec62b1ab0f4ccbc48aa8b9852cc25b38a1f12d1e Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Thu, 24 Aug 2017 21:13:57 +0800 Subject: [PATCH] iommu/amd: Check if domain is NULL in get_domain() and return -EBUSY In get_domain(), 'domain' could be NULL before it's passed to dma_ops_domain() to dereference. And the current code calling get_domain() can't deal with the returned 'domain' well if its value is NULL. So before dma_ops_domain() calling, check if 'domain' is NULL, If yes just return ERR_PTR(-EBUSY) directly. Reported-by: Dan Carpenter Fixes: df3f7a6e8e85 ('iommu/amd: Use is_attach_deferred call-back') Signed-off-by: Baoquan He Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 9e8ea1907796..b531307a9360 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2472,6 +2472,9 @@ static struct protection_domain *get_domain(struct device *dev) domain = to_pdomain(io_domain); attach_device(dev, domain); } + if (domain == NULL) + return ERR_PTR(-EBUSY); + if (!dma_ops_domain(domain)) return ERR_PTR(-EBUSY);