CVE-2026-98370

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

xfrm: fix compat ALLOCSPI request use-after-free

xfrm_state_netlink() builds the ALLOCSPI response with

dump_one_state(), which already calls alloc_compat() with the response

skb and header.

xfrm_alloc_userspi() then calls alloc_compat() again, but passes the

original request skb and its header. For a compat request, the

translator therefore interprets the 228-byte compat xfrm_userspi_info

as the 232-byte native layout and reads four bytes past the declared

payload. It also publishes the translated child through the request's

frag_list.

A multicast clone of the request shares skb_shared_info and can observe

that child. xfrm_user_rcv_msg() frees it after the request handler

returns, racing a compat receiver which may still be copying from it and

resulting in a use-after-free.

Remove the redundant conversion. The response keeps its correct compat

translation from dump_one_state(), and no child is attached to the

inbound request.