Novel N-acylsulfonamides, novel mixtures of herbicides and antidotes, and their use Safeners against phytotoxic side effects of pesticides in crop plants are compounds of the formula (I) and salts thereof where R1 is hydrogen, a hydrocarbon radical, a hydrocarbonoxy radical, a hydrocarbonthio radical or a heterocyclyl radical, each of the last-mentioned 4 radicals being unsubstituted or substituted by one or more identical or different radicals selected from the group consisting of halogen, cyano, nitro, amino, hydroxyl, carboxyl, formyl, carboxamide, sulfonamide and radicals of the formula —Za—Ra R2 is hydrogen or (C1-C4)-alkyl or R1 and R2 together with the group of the formula —CO—N— are the radical of a 3- to 8-membered saturated or unsaturated ring and R3 to R5, n and m are as defined in claim 1. The compounds can be prepared by the process of claim 8.