!5994 ipv6: sr: fix possible use-after-free and null-ptr-deref

Merge Pull Request from: @ci-robot 
 
PR sync from: Liu Jian <liujian56@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/XMQ52S5A37IC2UF2B25HBCMTUIMAJG5K/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9E3E4 
 
Link:https://gitee.com/openeuler/kernel/pulls/5994

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>