iommu: Check the result of iommu_group_get() for NULL
The result of iommu_group_get() was being blindly used in both
attach and detach which results in a dereference when trying
to work with an unknown device.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3de5c0b..69fef99 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1303,6 +1303,9 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
int ret;
group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
/*
* Lock the group to make sure the device-count doesn't
* change while we are attaching
@@ -1341,6 +1344,8 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
struct iommu_group *group;
group = iommu_group_get(dev);
+ if (!group)
+ return;
mutex_lock(&group->mutex);
if (iommu_group_device_count(group) != 1) {