From f2f101f6bcb3c47a432543dd309056e58192550f Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Fri, 11 Nov 2016 17:59:23 +0000 Subject: [PATCH] iommu/amd: Fix group refcounting If acpihid_device_group() finds an existing group for the relevant devid, 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. Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 754595ee11b6..019e02707cd5 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -373,6 +373,8 @@ static struct iommu_group *acpihid_device_group(struct device *dev) if (!entry->group) entry->group = generic_device_group(dev); + else + iommu_group_ref_get(entry->group); return entry->group; }