CVE-2025-40206 netfilter: nft_objref: validate objref and objrefmap expressions

In the Linux kernel, the following vulnerability has been resolved: netfilter: nftobjref: validate objref and objrefmap expressions Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls: BUG: TASK stack guard page was hit at 000000008bda5b8c...