Linux Kernel CVE-2026-72093

The amdxdna driver is the Linux kernel subsystem for AMD XDna AI accelerators (found in Ryzen AI silicon, e.g., Phoenix/Hawk Point/Strix Point APUs). The vulnerable function amdxdna_gem_dmabuf_mmap() manages GEM (Graphics Execution Manager) DMA buffer memory mappings via the DRM subsystem. The root cause is a classic use-after-free (CWE-416): the error path in the vm_insert_pages() failure branch calls vma->vm_ops->close(vma), which internally chains through drm_gem_vm_close() to drm_gem_object_put(), dropping the GEM object's reference count. If that was the last reference, the kernel frees the object. The code then falls through to the put_obj label and calls drm_gem_object_put() a second time on the now-freed object, constituting heap use-after-free. The fix replaces fall-through with a direct return from close_vma, ensuring the object put is performed exactly once. Affected commit range begins at e486147c912f653ef4b60a6c7dbd4168a4c56a9f (introduction of the vulnerable code).