cifs: Fix memory and information leak in smb3_reconfigure()

In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the
function returns immediately without freeing and erasing the newly
allocated new_password and new_password2. This causes both a memory leak
and a potential information leak.

Fix this by calling kfree_sensitive() on both password buffers before
returning in this error case.

Fixes: 0f0e357 ("cifs: during remount, make sure passwords are in sync")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: GoodLuck612

fs/smb/client/fs_context.c

@@ -1139,6 +1139,8 @@ static int smb3_reconfigure(struct fs_context *fc)
 	rc = smb3_sync_session_ctx_passwords(cifs_sb, ses);
 	if (rc) {
 		mutex_unlock(&ses->session_mutex);
+		kfree_sensitive(new_password);
+		kfree_sensitive(new_password2);
 		return rc;
 	}