diff
< 	if (n_rules > coalesce->n_rules)
< 	new_coalesce.rules = kcalloc(n_rules, sizeof(new_coalesce.rules[0]), GFP_KERNEL);
---
> 	if (n_rules == 0 || n_rules > coalesce->n_rules)
> 		return -EINVAL; // or another appropriate error code
> 	new_coalesce.rules = kcalloc(n_rules, sizeof(new_coalesce.rules[0]), GFP_KERNEL);
