CVE-2025-21940 drm/amdkfd: Fix NULL Pointer Dereference in KFD queue

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix NULL Pointer Dereference in KFD queue Through KFD IOCTL Fuzzing we encountered a NULL pointer derefrence when calling kfdqueueacquirebuffers. cherry picked from commit 049e5bf3c8406f87c3d8e1958e0a16804fa1d530...