Greg, This is for 4.14 LTS and 4.16. Thanks, Martijn On Fri, Feb 16, 2018 at 9:47 AM, Martijn Coenen <maco@xxxxxxxxxxx> wrote: > To prevent races with ep_remove_waitqueue() removing the > waitqueue at the same time. > > Reported-by: syzbot+a2a3c4909716e271487e@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx> > --- > drivers/android/binder.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/android/binder.c b/drivers/android/binder.c > index 15e3d3c2260d..359220f87e1d 100644 > --- a/drivers/android/binder.c > +++ b/drivers/android/binder.c > @@ -4376,6 +4376,15 @@ static int binder_thread_release(struct binder_proc *proc, > > binder_inner_proc_unlock(thread->proc); > > + /* > + * This is needed to avoid races between wake_up_poll() above and > + * and ep_remove_waitqueue() called for other reasons (eg the epoll file > + * descriptor being closed); ep_remove_waitqueue() holds an RCU read > + * lock, so we can be sure it's done after calling synchronize_rcu(). > + */ > + if (thread->looper & BINDER_LOOPER_STATE_POLL) > + synchronize_rcu(); > + > if (send_reply) > binder_send_failed_reply(send_reply, BR_DEAD_REPLY); > binder_release_work(proc, &thread->todo); > -- > 2.16.1.291.g4437f3f132-goog > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
