In the Linux kernel, the following vulnerability has been resolved:
iommu/mediatek: Fix NULL pointer deference in mtkiommudevice_group
Currently, mtkiommu calls during probe iommudeviceregister before the hwlist from driver data is initialized. Since iommu probing issue fix, it leads to NULL pointer dereference in mtkiommudevicegroup when hwlist is accessed with listfirstentry (not null safe).
So, change the call order to ensure iommudeviceregister is called after the driver data are initialized.