CVE-2026-43084

Summary

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

netfilter: nfnetlink_queue: make hash table per queue

Sharing a global hash table among all queues is tempting, but it can cause crash:

BUG: KASAN: slab-use-after-free in nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] [..] nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] nfnetlink_rcv_msg+0x46a/0x930 kmem_cache_alloc_node_noprof+0x11e/0x450

struct nf_queue_entry is freed via kfree, but parallel cpu can still encounter such an nf_queue_entry when walking the list.

Alternative fix is to free the nf_queue_entry via kfree_rcu() instead, but as we have to alloc/free for each skb this will cause more mem pressure.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/22730cb96093b5be0609063bbb1923dbecd61252
• https://git.kernel.org/stable/c/41e3652a178cb0eecd48e0e6e27fbb73a004046a
• https://git.kernel.org/stable/c/9e5ebef91120d2764aefe557c3a484b6288f341f
• https://git.kernel.org/stable/c/936206e3f6ff411581e615e930263d6f8b78df9d

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