iommu: Fix wrong freeing of iommu_device->dev

The struct iommu_device has a 'struct device' embedded into
it, not as a pointer, but the whole struct. In the
conversion of the iommu drivers to use struct iommu_device
it was forgotten that the relase function for that struct
device simply calls kfree() on the pointer.

This frees memory that was never allocated and causes memory
corruption.

To fix this issue, use a pointer to struct device instead of
embedding the whole struct. This needs some updates in the
iommu sysfs code as well as the Intel VT-d and AMD IOMMU
driver.

Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Fixes: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device')
Cc: stable@vger.kernel.org # >= v4.11
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 11 insertions, 1 deletions

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2cb54adc4a33..176f7569d874 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -240,7 +240,7 @@ struct iommu_device {
 	struct list_head list;
 	const struct iommu_ops *ops;
 	struct fwnode_handle *fwnode;
-	struct device dev;
+	struct device *dev;
 };
 
 int  iommu_device_register(struct iommu_device *iommu);
@@ -265,6 +265,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
 	iommu->fwnode = fwnode;
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+	return (struct iommu_device *)dev_get_drvdata(dev);
+}
+
 #define IOMMU_GROUP_NOTIFY_ADD_DEVICE		1 /* Device added */
 #define IOMMU_GROUP_NOTIFY_DEL_DEVICE		2 /* Pre Device removed */
 #define IOMMU_GROUP_NOTIFY_BIND_DRIVER		3 /* Pre Driver bind */
@@ -589,6 +594,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
 {
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+	return NULL;
+}
+
 static inline void iommu_device_unregister(struct iommu_device *iommu)
 {
 }