Re: [PATCH] udc: Memory leak on error path and use after free

From: Alan Stern
Date: Wed Aug 16 2017 - 11:29:16 EST


On Wed, 16 Aug 2017, Anton Vasilyev wrote:

> gadget_release() is responsible for cleanup dev memory.
> But if net2280_probe() fails after dev allocation, then
> gadget_release() become unregistered and dev memory leaks.

This isn't needed if usb_add_gadget_udc_release() is fixed, right?

> Also net2280_remove() calls usb_del_gadget_udc() which
> perform schedule_delayed_work() with gadget_release(), so
> it is possible that dev will be deallocated exactly after
> this call and leads to use after free.

Where is there a possible use after free?

> The patch moves deallocation from gadget_release() to
> net2280_remove().

Alan Stern