55%
18%
60%
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.
CVSS 3.1 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
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