From 44cd613c0e4cd93079ea2a93aa06649d8ca0830a Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 2 Dec 2009 10:18:30 +0000 Subject: [PATCH] intel-iommu: Fix oops with intel_iommu=igfx_off The hotplug notifier will call find_domain() to see if the device in question has been assigned an IOMMU domain. However, this should never be called for devices with a "dummy" domain, such as graphics devices when intel_iommu=igfx_off is set and the corresponding IOMMU isn't even initialised. If you do that, it'll oops as it dereferences the (-1) pointer. The notifier function should check iommu_no_mapping() for the device before doing anything else. Cc: stable@kernel.org Signed-off-by: David Woodhouse --- drivers/pci/intel-iommu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 83cabdc118db..e3e84cac0e98 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -3247,6 +3247,9 @@ static int device_notifier(struct notifier_block *nb, struct pci_dev *pdev = to_pci_dev(dev); struct dmar_domain *domain; + if (iommu_no_mapping(dev)) + return 0; + domain = find_domain(pdev); if (!domain) return 0;