In the Linux kernel, the following vulnerability has been resolved: drm/vc4: hvs/v3d: Fix null...

In the Linux kernel, the following vulnerability has been resolved:

drm/vc4: hvs/v3d: Fix null dereference in unbind

The hvs and v3d drivers use dev_get_drvdata(master) in their unbind functions. Since the vc4-drm gets removed before its dependent drivers (vc4_hvs/vc4_v3d) the vc4_hvs_unbind/vc4_v3d_unbind functions try to get drvdata of its master and fails with a null dereference error.

Use the data pointer passed to the unbind functions directly instead of dev_get_drvdata(master). This avoids using potentially freed memory.