!4891 Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhengchao Shao <shaozhengchao@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/I3JU75I4KGIVETOUHERVF5UKLKSYLSX6/ 
 
https://gitee.com/src-openeuler/kernel/issues/I8YV3O 
 
Link:https://gitee.com/openeuler/kernel/pulls/4891

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>