Re: [PATCH] binder: don't detect sender/target during buffer cleanup

From: Dan Carpenter
Date: Tue Nov 02 2021 - 09:24:09 EST


On Fri, Oct 15, 2021 at 04:38:11PM -0700, Todd Kjos wrote:
> When freeing txn buffers, binder_transaction_buffer_release()
> attempts to detect whether the current context is the target by
> comparing current->group_leader to proc->tsk. This is an unreliable
> test. Instead explicitly pass an 'is_failure' boolean.
>
> Detecting the sender was being used as a way to tell if the
> transaction failed to be sent. When cleaning up after
> failing to send a transaction, there is no need to close
> the fds associated with a BINDER_TYPE_FDA object. Now
> 'is_failure' can be used to accurately detect this case.
>

It's really hard for me to understand what this bug looks like to the
user? Is it a memory leak or do we free the wrong thing?

regards,
dan carpenter