Yes, that's right!

Volcanic eruptions eject large quantities of sulphur dioxide into the upper atmosphere (stratosphere). Water droplets condense on the sulphur dioxide and form clouds. The clouds reflect the sunlight back so that the layers below are cooled down and the layers above are warmed up.

Source: IPCC 2014: Climate Change 2013: Scientific Basis. Frequently asked questions and answers - part of the contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) [T.F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. German translation by the German IPCC Coordination Office and Climate Office for Polar Regions and Sea Level Rise, Bonn, 2017. at: https://www.deutsches-klima-konsortium.de/de/klimafaq-11-2.html#:~:text=Gro%C3%9Fe%20Vulkanausbr%C3%BCche%20beeinflussen%20das%20Klima,dadurch%20Wolken%20aus%20Schwefels%C3%A4uretr%C3%B6pfchen%20bildet (last accessed on 04/05/2023)