New rider here, can anybody help me identify what is this tube near the side stand and why it leaks that black thingy you can see on the ground? Thanks in advance! (Bike's a 2017 sv650)

https://i.redd.it/xu34zsh1h1821.jpg via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/abv23o/new_rider_here_can_anybody_help_me_identify_what/?utm_source=ifttt