How to push data in appsrc without freeing memory?

I push data in an appsrc element with gst_app_src_push_buffer.

Data is mmaped from a fixed DMA memory allocation.

I'm currently using GstBuffer *buffer = gst_buffer_new_wrapped_full to 
wrap data in the gstreamer buffer that is passed.

Even if the notify function is null, the framework is still trying to 
free my data.

It's actually "working" but freeing mapped memory and continuing to use 
it is certainly not a good idea.

I obviously don't want to memcpy data. What is the proper way to wrap 
data in a GstBuffer structure so that gstreamer never tries to free the 
memory?

Thank you in advance,

Grégoire