Striker Luke Howsen took his tally of league goals to 24 with a hat-trick while Oliver Hurst and Paul Wilkin were also on target.
Oldroyd has now netted 21 times this season for Earby whose remaining two goals were scored by James Holmes.
White Star now know who their opponents will be in the final of the Division One League Cup at Sutton Playing Fields on May 7. Grassington United overcame a determined Gargrave side 4-2 on penalties, after a 3-3 draw.
Stuart Gee, Tarek Issa and Paul Wright were on target for Grassington United while William Beckwith, Liam Jameson and Andy Seddon netted for Gargrave.
Matthew Blackwell scored four times as second-bottom Earby Town Reserves won 6-0 at Ingrow & Worth Valley in Division Two. Lee Roberts and Bill Russell were also on target.
Chris Hogg’s first-half goal for Bradley was cancelled out by a Joseph Parker strike as Skipton hit back to force a 1-1 draw.
All of the goals came in the first half as Oxenhope Recreation defeated Settle United 3-0 to secure second place in Division Three.
Andrew Fox, Connor Madden and William Wells were all on target as Oxenhope secured a promotion place.
Salts showed no mercy for struggling Ilkley as they cruised to a 7-1 win. Jonny Dwyer (2), Ross Barraclough, Sean Holmes, Pat McHale, Ryan Mullin and Jack Slinger.
Skipton Town Reserves will meet Pendle Renegades in the Division Four League Cup final at the Coulthurst Ground on Tuesday (6.30pm) after beating table-topping Manningham All Stars on penalties.
The two teams were locked 3-3 at the end of extra-time, Ross Greenwood, Josh Newton and Jason Martin scoring for Town.
The penalty shoot out was dominated by the Skipton side as they ran out 4-1 winners.