Is the salary of someone who works in a shop that sells men's shorts that reach the knee, and a part of the thigh becomes visible when sitting while wearing them, permissible?

Working in the shop and its salary are permissible (halal), and selling shorts is permissible. What they reveal can be worn in situations where there is no حرمة (sacredness/prohibition). Prohibition only occurs if it is known with certainty that the buyer will use them in a forbidden way. It is worth noting that the issue of uncovering the thigh is a matter of scholarly disagreement.