I assume you are referring to the discussion of attacking Dol Guldur at the meeting of the White Council. Since we are never actually given detail of how the proposed attack was to take place, we can't definitively say that it would have been a violation of their charge. At this point (presumably talking about the meeting portrayed in the Hobbit, which was portraying the meeting of 2851), they did not know for certain that Sauron was there (movie version). In the novel, Galdalf had found out by this point that it was Sauron, but Saruman did not want to disrupt his searching for the ring. By the time they did (in 2941 in the novel's timeline), they did attack, although we are not given details about exactly who took place in the attack, other than it was "The White Council".
When Dol Guldur was actually destroyed, in 3019 TA, it was not the greater White Council that did it, it was "merely" the elves. (I don't have the appendices avaliable at the moment)
The elves, led by Thranduil of Mirkwood and Galadriel of Lorien led an assault on Dol Guldur and Galadriel herself threw down its walls, and laid its pits bare. Absolutely nothing of the fortress that had stood for 2,019 years was left. Renamed back to Amon Lanc, it became the capital of Celeborn's realm of East Lórien in the Fourth Age, while he remained in Middle-earth.
Presumably Galadriel herself also took part in the first attack that drove Sauron out, and into Mordor. Who knows what they would have done if they thought they could have taken Barad-Dur, though I doubt they ever would have tried, given the difficulty of attacking Mordor by frontal assault.