How to get rid of a rotten meat smell?

Clean all surfaces with Odo-Ban, not just the ones that it touched. It's a cleaner, disinfectant, and has a pleasant scent. You can also spray in the air as a freshener.

Where is it coming from?

Put a bowl of white vinegar in the area and it will eat the smells. Replenish as needed.

If you have had meat spoil in a freezer or fridge that is made out of plastic, as opposed to stainless steel, it can be extremely difficult to eradicate the smell.

Also if any fabric items have been exposed to the spoiled meat, it may also be very hard to rid them of the odour.

Where was the rotten meat?