How to change the site logo of sharepoint online (Office 365) using C#?

For uploading file you are use below snippet

/// <summary>
/// Uploads the specified file to a SharePoint site
/// </summary>
/// <param name="url">site url</param>
/// <param name="creds">Credentials</param>
/// <param name="listTitle">List Title</param>
/// <param name="fileName">File Name</param>
private static void UploadFile(string url, ICredentials creds, string listTitle,string fileName)
{
      using (var clientContext = new ClientContext(url))
      {
           clientContext.Credentials = creds;

           using (var fs = new FileStream(fileName, FileMode.Open))
           {
               var fi = new FileInfo(fileName);
               var list = clientContext.Web.Lists.GetByTitle(listTitle);
               clientContext.Load(list.RootFolder);
               clientContext.ExecuteQuery();
               var fileUrl = String.Format("{0}/{1}", list.RootFolder.ServerRelativeUrl, fi.Name);

               Microsoft.SharePoint.Client.File.SaveBinaryDirect(clientContext, fileUrl, fs, true);
            }
       }
  }

For setting site logo you can use SiteLogoUrl property. Its supported in CSOM https://officespdev.uservoice.com/forums/224641-general/suggestions/6234945-make-the-sitelogourl-property-available-in-csom