[ Upstream commit 237ff253f2d4f6307b7b20434d7cbcc67693298b ] Added initialization use_ack to mptcp_parse_option(). Reported-by: syzbot+b834a6b2decad004cfa1@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>