The bug `KASAN: slab-use-after-free in qxl_mode_dumb_create` is reproduced on 5.10 stable branch.
The problem has been fixed by the following patch which can be cleanly applied to 5.10. The fix is already included in all stable branches starting from 5.15. Link to the "failed to apply to 5.10" report [1]. [1]: https://lore.kernel.org/stable/2023082121-mumps-residency-9108@gregkh/
