Stop it before it's created
You could use manacles, traps, rope, chains, cages and all sort of mundane and magical contraptions to keep the creature restrained while you use your Command and/or Control Undead abilities to gain control. Masterwork manacles have a Strength DC of 28, while Mithril manacles have a DC of 30 and are naturally more durable. A Sawtooth Bear Trap has a Strength DC of 32.
While those aren't checks too difficult for such a creature, they would require multiple checks to escape all of them, giving you enough time to apply debuffs and try to control it again.
If the undead is created while already trapped inside a Crushing Cage Trap, it can't possibly get out of it without help. Though this trap specifically is limited to a 10-foot square area.
Spells like Shackle may also help with that. Consecrate helps lowering their saves for as long as they remain in the area. While Prayer will apply a penalty to all enemies regardless of their level or stats.
If your caster level is higher than the creature's HD, you could try using Undead Ward to prevent it from passing through the designed area. Considering they are Linorm dragons, that is unlikely though. But spells like Leashed Shackles, or even Forcecage have better odds at succeeding.
Other class's abilities
Void school wizards (Dragon Empires Primer) also may reduce saving throws of any creatures with no saving throw to resist it. Clerics with the Madness domain have a similar ability, and those with the Chaos domain may force a creature to roll two dice and take the lowest result.
Mesmerists may also apply a penalty to saving throws using their Hypnotic Stare if they also got Psychic Inception.