drm/exynos VIDI Deref

Vulnerability analysis

The root cause is incorrect device pointer retrieval in vidi_connection_ioctl() - it fetches driver_data from drm_dev->dev (the exynos-drm master device) instead of the VIDI component device. The driver_data in the master device is a completely different device, not the vidi component. This results in access to uninitialized or garbage pointer values, which can cause null pointer dereferences, out-of-bounds memory access, or use-after-free conditions depending on what garbage data is interpreted as a pointer. The fix stores the correct VIDI device pointer in exynos_drm_private->vidi_dev during bind/unbind operations and uses this stored pointer for safe context lookup in the ioctl handler, adding a NULL check for safety. The attack surface is local-only through DRM device ioctls, requiring access to /dev/dri/* devices which typically needs graphics group membership or similar low privileges.