CVE-2024-44973

In the Linux kernel, the following vulnerability has been resolved:
mm, slub: do not call do_slab_free for kfence object
In 782f8906f805 the freeing of kfence objects was moved from deep
inside do_slab_free to the wrapper functions outside. This is a nice
change, but unfortunately it missed one spot in __kmem_cache_free_bulk.
This results in a crash like this:
BUG skbuff_head_cache (Tainted: G S B E ): Padding overwritten.
0xffff88907fea0f00-0xffff88907fea0fff @offset=3840
slab_err (mm/slub.c:1129)
free_to_partial_list (mm/slub.c:? mm/slub.c:4036)
slab_pad_check (mm/slub.c:864 mm/slub.c:1290)
check_slab (mm/slub.c:?)
free_to_partial_list (mm/slub.c:3171 mm/slub.c:4036)
kmem_cache_alloc_bulk (mm/slub.c:? mm/slub.c:4495 mm/slub.c:4586
mm/slub.c:4635)
napi_build_skb (net/core/skbuff.c:348 net/core/skbuff.c:527
net/core/skbuff.c:549)
All the other callers to do_slab_free appear to be ok.
Add a kfence_free check in __kmem_cache_free_bulk to avoid the crash.