config_red divides by (max_th-min_th) and max_th without zero/negative check: kernel panic via setsockopt

Summary

config_red(:1346-1350): x->c_1=ioc_fs->max_p/(ioc_fs->max_th-ioc_fs->min_th). If max_th==min_th -> div by zero -> #DE -> kernel panic. If DN_IS_GENTLE_RED and max_th==0: x->c_3=(SCALE(1)-max_p)/max_th -> div by zero. set_fs_parms ignores return value (:1447 "XXX should check errors"). Requires raw IP socket (root).