Re: [PATCH 3/3] ANDROID: binder: fix proc->tsk check.

From: John Stultz
Date: Mon Aug 21 2017 - 14:48:48 EST


On Tue, Aug 8, 2017 at 11:08 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Aug 08, 2017 at 10:34:47AM -0700, John Stultz wrote:
>> On Fri, Jul 28, 2017 at 4:56 AM, Martijn Coenen <maco@xxxxxxxxxxx> wrote:
>> > Commit c4ea41ba195d ("binder: use group leader instead of open thread")'
>> > was incomplete and didn't update a check in binder_mmap(), causing all
>> > mmap() calls into the binder driver to fail.
>> >
>> > Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx>
>> > ---
>> > drivers/android/binder.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/android/binder.c b/drivers/android/binder.c
>> > index f7665c31feca..831cdd7d197d 100644
>> > --- a/drivers/android/binder.c
>> > +++ b/drivers/android/binder.c
>> > @@ -3362,7 +3362,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>> > const char *failure_string;
>> > struct binder_buffer *buffer;
>> >
>> > - if (proc->tsk != current)
>> > + if (proc->tsk != current->group_leader)
>> > return -EINVAL;
>> >
>> > if ((vma->vm_end - vma->vm_start) > SZ_4M)
>>
>> Tested-by: John Stultz <john.stultz@xxxxxxxxxx>
>>
>> As Amit already confirmed, this resolves the wifi and bluetooth
>> regression I was seeing with Android using 4.13-rc2.
>>
>> Though I've not seen it show up in Linus' tree yet, so I wanted to
>> pester folks so it gets into 4.13-rc (its given me some slight grief
>> trying to bisect down a separate issue).
>
> I will queue this up in the next few days, I need to resolve the patches
> that have been sent to me for this, sorry for the delay.

Hey Greg,
Sorry to pester you again on this, but this seems to still be
missing in -rc6. Don't want it to slip by.

thanks
-john