Talcum powder or cornstarch will absorb oils from leather. Leave some overnight on the stain. If the oil is still in the leather, I suggest throwing it away. If your bag is faux leather, try lighter fluid instead. Probably won't remove the smell? I'm not sure. Check the composition personally & Google accordingly.

Leather soaks in oil like a mf so it may not be salvageable. Also depends on the oil.

Source: Haberdasher/Upholsterer/Curtain Maker/Tailor in a past life.