!8521 isofs: Fix out of bound access for corrupted isofs image

Merge Pull Request from: @ci-robot 
 
PR sync from: Guo Mengqi <guomengqi3@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/26HGXRHFIH3Z5NNYYK5WLQTSSXKIO7JD/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9RD2M 
 
Link:https://gitee.com/openeuler/kernel/pulls/8521

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>