From 0774e392555a128cff7a94929b9ce957927fef49 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 28 Sep 2012 16:14:44 +0200 Subject: [PATCH] iommu/amd: Fix wrong assumption in iommu-group specific code The new IOMMU groups code in the AMD IOMMU driver makes the assumption that there is a pci_dev struct available for all device-ids listed in the IVRS ACPI table. Unfortunatly this assumption is not true and so this code causes a NULL pointer dereference at boot on some systems. Fix it by making sure the given pointer is never NULL when passed to the group specific code. The real fix is larger and will be queued for v3.7. Reported-by: Florian Dazinger Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index b64502d..e89daf1 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -266,7 +266,7 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to) static int iommu_init_device(struct device *dev) { - struct pci_dev *dma_pdev, *pdev = to_pci_dev(dev); + struct pci_dev *dma_pdev = NULL, *pdev = to_pci_dev(dev); struct iommu_dev_data *dev_data; struct iommu_group *group; u16 alias; @@ -293,7 +293,9 @@ static int iommu_init_device(struct device *dev) dev_data->alias_data = alias_data; dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff); - } else + } + + if (dma_pdev == NULL) dma_pdev = pci_dev_get(pdev); /* Account for quirked devices */ -- 2.7.4