From 3ee9eca760e7d0b68c55813243de66bbb499dc3b Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Tue, 16 Jul 2019 22:38:06 +0100 Subject: [PATCH] iommu/vt-d: Check if domain->pgd was allocated There is a couple of places where on domain_init() failure domain_exit() is called. While currently domain_init() can fail only if alloc_pgtable_page() has failed. Make domain_exit() check if domain->pgd present, before calling domain_unmap(), as it theoretically should crash on clearing pte entries in dma_pte_clear_level(). Cc: David Woodhouse Cc: Joerg Roedel Cc: Lu Baolu Cc: iommu@lists.linux-foundation.org Signed-off-by: Dmitry Safonov Reviewed-by: Lu Baolu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 72c6d647bec9..bdaed2da8a55 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1890,7 +1890,6 @@ static int domain_init(struct dmar_domain *domain, struct intel_iommu *iommu, static void domain_exit(struct dmar_domain *domain) { - struct page *freelist; /* Remove associated devices and clear attached or cached domains */ domain_remove_dev_info(domain); @@ -1898,9 +1897,12 @@ static void domain_exit(struct dmar_domain *domain) /* destroy iovas */ put_iova_domain(&domain->iovad); - freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw)); + if (domain->pgd) { + struct page *freelist; - dma_free_pagelist(freelist); + freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw)); + dma_free_pagelist(freelist); + } free_domain_mem(domain); }