CVE-2026-52981

Description

In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb.

References

• https://git.kernel.org/stable/c/0084712e0bee204b284510cdb63182fd5a30c2b7
• https://git.kernel.org/stable/c/4438113be604ee67a7bf4f81da6e1cca41332ce4
• https://git.kernel.org/stable/c/445e45a2c3a078316a62d2d331a570cf34ef5079
• https://git.kernel.org/stable/c/63063ba60d2dc334e34f1e3f9271d7f3f6f30307
• https://git.kernel.org/stable/c/8a89054a1ec0767aec25ed2bbac933da6ba3cf5a