In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null pointer check for getfirstactive_display()
The function modhdcphdcp1enableencryption() calls the function getfirstactivedisplay(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference in modhdcphdcp2enable_encryption().
Add a null pointer check for getfirstactivedisplay() and return MODHDCPSTATUSDISPLAYNOTFOUND if the function return null.