CVE-2026-52976

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

drm/xe: Fix error cleanup in xe_exec_queue_create_ioctl()

Two error handling issues exist in xe_exec_queue_create_ioctl():

1. When xe_hw_engine_group_add_exec_queue() fails, the error path jumps
   to put_exec_queue which skips xe_exec_queue_kill(). If the VM is in
   preempt fence mode, xe_vm_add_compute_exec_queue() has already added
   the queue to the VM's compute exec queue list. Skipping the kill
   leaves the queue on that list, leading to a dangling pointer after
   the queue is freed.

2. When xa_alloc() fails after xe_hw_engine_group_add_exec_queue() has
   succeeded, the error path does not call
   xe_hw_engine_group_del_exec_queue() to remove the queue from the hw
   engine group list. The queue is then freed while still linked into
   the hw engine group, causing a use-after-free.

Fix both by:
- Changing the xe_hw_engine_group_add_exec_queue() failure path to jump
  to kill_exec_queue so that xe_exec_queue_kill() properly removes the
  queue from the VM's compute list.
- Adding a del_hw_engine_group label before kill_exec_queue for the
  xa_alloc() failure path, which removes the queue from the hw engine
  group before proceeding with the rest of the cleanup.

(cherry picked from commit 37c831f401746a45d510b312b0ed7a77b1e06ec8)