CVE-2026-68245: Concurrent Execution using Shared Resource with Improper Synchronization

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

drm/amdgpu: fix lifetime issue of amdgpu_vm_get_task_info_pasid()

The vm pointer returned from amdgpu_vm_get_vm_from_pasid() is only valid while the lock is still being held. Once xa_unlock_irqrestore is called and returned, the pointer is no longer under lock and is subject to modification. Since, the caller still dereferences vm->task_info in amdgpu_vm_get_task_info_vm() after the lock is removed, this causes a use after unlock problem.

Remove the lifetime issue present in amdgpu_vm_get_task_info_pasid() through removing the amdgpu_vm_get_vm_from_pasid() function from amdgpu_vm.c and making the relevant code inline to hold the lock while it is still in use.

(cherry picked from commit 9d01579f3f868b333acc901815972685989092c7)