[PATCH RESEND] android: binder: Sanity check at binder ioctl

[chenfeng]

On 2016/1/19 15:33, Greg KH wrote:
> On Tue, Jan 19, 2016 at 11:45:36AM +0800, Chen Feng wrote:
>> When a process fork a child process, we should not allow the
>> child process use the binder which opened by parent process.
>>
>> But if the binder-object creater is a thread of one process who exit,
>> the other thread can also use this binder-object normally.
>> We can distinguish this by the member proc->tsk->mm.
>> If the thread exit the tsk->mm will be NULL.
>>
>> proc->tsk->mm != current->mm && proc->tsk->mm
>>
>> So only allow the shared mm_struct to use the same binder-object and
>> check the existence of mm_struct.
>>
>> Signed-off-by: Chen Feng <puck.chen at hisilicon.com>
>> Signed-off-by: Wei  Dong <weidong2 at hisilicon.com>
>> Signed-off-by: Junmin Zhao <zhaojunmin at huawei.com>
>> Reviewed-by: Zhuangluan Su <suzhuangluan at hisilicon.com>
>> ---
>>  drivers/android/binder.c | 2 ++
>>  1 file changed, 2 insertions(+)
> 
> Why resend?  What changed from the previous version?
> 
My fault, it's my error commit.
mistake the current->mm with current->tsk->mm.
The robot-compile finds out this error.
> greg k-h
> 
> .
>