default or selected kernelversion does not have config value CONFIG_SET_FS.
Result is shown for kernelversion 6.9.9

CONFIG_SET_FS (not configurable)

configname: CONFIG_SET_FS

Linux Kernel Configuration
└─>General architecture-dependent options
└─>SET_FS
In linux kernel since version 5.1 (release Date: 2019-05-05)