CVE-2023-52825

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

drm/amdkfd: Fix a race condition of vram buffer unref in svm code

prange->svm_bo unref can happen in both mmu callback and a callback after
migrate to system ram. Both are async call in different tasks. Sync svm_bo
unref operation to avoid random "use-after-free".