Undefined Downstream is two releases behind. My script identifies the following fixes which should be backported on top:
95017b8c8f10a ("tests: shell: fix spurious dump failure in vmap timeout test")
570320ab9a075 ("libnftables-json: fix raw payload expression documentation")
20f1c60ac8c88 ("src: collapse set element commands from parser")
42b081df74772 ("rule: netlink attribute offset is uint32_t for struct nlerr_loc")
68d2de3ca6c6e ("src: fix extended netlink error reporting with large set elements")
193faa5475a5d ("json: collapse set element commands from parser")
c1c0c54e237c8 ("tests: py: Fix for storing payload into missing file")
Extra fixes missing a tag:
c416416b03d80 ("tests: monitor: fix up test case breakage")
Features worth backporting while at it:
be4b61c05a249 ("doc: extend description of fib expression")
bb6312484af93 ("json: Support typeof in set and map types")
73a8adfc2432e ("monitor: Recognize flowtable add/del events")
