CVE-2025-40348 slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts

In the Linux kernel, the following vulnerability has been resolved: slab: Avoid race on slab-objexts in allocslabobjexts If two competing threads enter allocslabobjexts and one of them fails to allocate the object extension vector, it might override the valid slab-objexts allocated by the other...