From e1b44cbe7b5d4d97e43a1476b68e0adc1aa5e383 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Fri, 11 Nov 2016 17:59:22 +0000 Subject: iommu/arm-smmu: Fix group refcounting When arm_smmu_device_group() finds an existing group due to Stream ID aliasing, it should be taking an additional reference on that group. Otherwise, the caller of iommu_group_get_for_dev() will inadvertently remove the reference taken by iommu_group_add_device(), and the group will be freed prematurely if any device is removed. Reported-by: Sricharan R Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel --- drivers/iommu/arm-smmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index c841eb7a1a74..b85fa2471738 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1466,7 +1466,7 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev) } if (group) - return group; + return iommu_group_ref_get(group); if (dev_is_pci(dev)) group = pci_device_group(dev); -- cgit v1.2.3-59-g8ed1b