In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: dp: drm_err => dev_err in HPD path to avoid NULL ptr
The function mtk_dp_wait_hpd_asserted() may be called before the
mtk_dp->drm_dev pointer is assigned in mtk_dp_bridge_attach().
Specifically it can be called via this callpath:
Using drm level prints anywhere in this callpath causes a NULL pointer dereference. Change the error message directly in mtk_dp_wait_hpd_asserted() to dev_err() to avoid this. Also change the error messages in mtk_dp_parse_capabilities(), which is called by mtk_dp_wait_hpd_asserted().
While touching these prints, also add the error code to them to make future debugging easier.