
< 	dec->numtiles = dec->numhtiles * dec->numvtiles;
---
> 	if (dec->numhtiles > 0 && dec->numvtiles > SIZE_MAX / dec->numhtiles) {
> 		return JPC_FAILURE; // Or appropriate error handling
> 	}
> 	dec->numtiles = dec->numhtiles * dec->numvtiles;
