[Fixed]-Setting model user to current user when using inlineformset_factory in Django

In this case I wouldn’t use a formset at all. If you need to collect user information to create the new listing, use a single ListingForm and AddressForm, save the new address, and then save the ListingForm with commit=False, assign the user and address to it, and then save the instance.

@login_required(login_url='share:login_view', redirect_field_name='share:addlisting')
def addlisting(request):
    if request.method == 'POST':
        address_form = AddressForm(request.POST, prefix="address")
        listing_form = ListingForm(request.POST, prefix="listing")
        if address_form.is_valid() and listing_form.is_valid():
            new_address = address_form.save()
            new_listing = listing_form.save(commit=False)
            new_listing.address = new_address
            new_listing.user = request.user
            new_listing.save()
            return HttpResponseRedirect(reverse('/listing_added/'))
    else:
        address_form = AddressForm(prefix="address")
        listing_form = ListingForm(prefix="listing")
    return render(request, 'share/addlisting.html', {
        "address_form": address_form,
        "listing_form": listing_form
    })

If you ever have a many-to-many relationship on Listings you’ll need to explicitly save those after saving the instance, as discussed here:
https://docs.djangoproject.com/en/1.10/topics/forms/modelforms/#the-save-method