Former military K9 handler here. Have trained over 20 military and police working K9s in my life, for everything from IED detection, to drug interdiction, to search and rescue, to wartime and law enforcement tactics. Have also owned and fully trained Schutzhund K9's and competed and have helped more than a few friends and family members with dogo problems at home. Not claiming to know it all, but have had a fairly broad and deep (and mostly successful history) with our furry best friends.
Soooo firstly, really cute pup, man! It is hard to look at a face like that and issue a reprimand. Some dogs like socks. Some like underwear. Some like couch and chair legs. Some like shoes. My son's dog used to literally chew on and eat rocks.
As some have indicated here, unfortunately, it is more than just a pain in the ass of losing socks, however. Your pooch could end up in a life and death situation, with you footing a $3000-$10000 vet bill for emergency abdominal surgery, going through the anxiety and pain of seeing your best friend hurting and struggling with pain, or God forbid tragically losing him.
As someone who absolutely loves dogs and loves seeing dogs and humans fully enjoy the blessings we bestow on one another, I recommend the following options.
1) Simple and quick way out: Buy some bitter apple spray (amazon or any pet store). Spray a few socks that you randomly leave in places he can find them. He will go for the sock and receive a solid negative reinforcement that socks are no longer something to chew on or eat. Yuck.
2) Slightly more work: using a long puppy lead and slack collar on him, also fill a squirt bottle with water, or a jar with pennies. Sucks to do it, but set him up with some socks randomly strewn about and pretend you are engrossed in TV or taking a nap. When he goes to get a sock, in a very firm and relatively loud voice (but without screaming) state "NO!", shake the jar of pennies or give him a spritz of water, then dive for that long puppy lead and give him a firm (but not too hard) correction snap to the collar. If the sock was in his mouth already, take it from him, show it too him in your hand and say "No!" again. Give him 30 - 45 seconds to get over the fear / anxiety portion of being corrected. Walk him to another location. Command him to sit or lie down, pet him and soothe him. Do this every day for until he stops going for the socks. Even once he stops, you should set him up and test him once every few weeks, so you nip the behavior in the bud, if he forgets and starts going for them again. You can also get what is called an e-Collar (but I don't recommend experimenting with this on your own.... find an experienced trainer (I recommend "offleashk9training.com) to work the problem and to teach you how to use the training tool effectively, cautiously and humanely....more on this at the bottom). If you go this route and decide not to use a trainer, as Dynamo87 recommended, work the sound warning first, and make sure to watch a lot of on line videos so you learn how to find the right stim level along with the sound, and that will ensure the least amount of discomfort possible while still making certain that the dog complies).
3) Advanced: Put your dog through a good basic obedience course to where he is solid on come, heel, sit, stay, down and place, and such that he is responsive to praise commands like "yes" and "good dog", as well as negative reinforcement statements like "No", "leave it", and "Bad dog". "Leave it" then becomes the effective command by which he knows he is not to mess with something, whether he is taking it in his mouth, sniffing at it, pulling towards it, or even just paying to much attention to it. Over time, he will come to realize that certain things are OK at some times and "leave it" at others, such as a toy that perhaps he can have outside, but not bring through the door and into the house, or perhaps a chewy that he can have while relaxing on the floor in front of the TV, but can't have when you decide its seen its last day and pick up to throw out, and he goes to take it from you. Eventually he will realize that socks are always "Leave it" (provided you pay close attention and always catch him in the act at first) and he will simply start to leave socks alone. This also works best with an eCollar.
There are all kinds of obedience courses, training tools, and some recently evolved VERY STRONG opinions on positive reinforcement only, versus using positive and negative reinforcement. I may get some backlash for recommending both positive and negative reinforcement for your training, and especially e-Collar which some consider cruel and inhumane, but I am old, and old school and I was responsible for training dogs that can save a life or take one.... and this is what worked for me without fail. Also considering that you usually only have to correct with an eCollar two or three times to permanently change a bad behavior, I consider that less cruel that yelling at and physically battling your dog, or worse yet, risking that improper behavior will place the dog in a circumstance of being injured or worse.
Clearly your dog is your family....and you need to research and decide what is right for you.
Wishing you best of luck in addressing the problem and many happy times with your pooch!