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

From: Greg KH
Date: Tue Aug 22 2017 - 11:50:00 EST


On Mon, Aug 21, 2017 at 11:48:39AM -0700, John Stultz wrote:
> 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.

It's not lost, just on the bottom of my queue, will catch up with it
next week...

thanks,

greg k-h