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Subject: Re: [PATCH RESEND] android: binder: Sanity check at binder ioctl
To: Greg KH <gregkh@linuxfoundation.org>
References: <1453175136-3351-1-git-send-email-puck.chen@hisilicon.com>
 <20160119073358.GA30483@kroah.com>
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From: chenfeng <puck.chen@hisilicon.com>
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Date: Tue, 19 Jan 2016 15:49:27 +0800
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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@hisilicon.com>
>> Signed-off-by: Wei  Dong <weidong2@hisilicon.com>
>> Signed-off-by: Junmin Zhao <zhaojunmin@huawei.com>
>> Reviewed-by: Zhuangluan Su <suzhuangluan@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
> 
> .
>