From: Pratham Pratap <prathampratap@codeaurora.org>
To: linux-usb@vger.kernel.org
Subject: ep0 request dequeue for function drivers
Date: Mon, 26 Apr 2021 13:42:50 +0530 [thread overview]
Message-ID: <655514e3-90c1-e628-d5e6-efb298f49038@codeaurora.org> (raw)
Hi,
Let's say a function driver queues a request on ep0 and before the
completion handler could run composition switch/physical disconnect
happens. This request will be in pending list since gadget_giveback is
not done but the composite driver will free the request from
composite_dev_cleanup. Now, once the next connect happens, another ep0
request is queued and while handling the completion of that request,
gadget driver might end up accessing the old/stale request leading to
list_poison since pending list is corrupted.
To fix this, the function drivers might want to use setup_pending(mark
it to true) flag so that when composite_dev_cleanup is run the requests
are given back from usb_ep_dequeue; clear the setup pending flag in
function driver when completion handler is run successfully. I can see
this issue in almost all the function drivers.
Looking for suggestions and comments.
--Pratham
next reply other threads:[~2021-04-26 8:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 8:12 Pratham Pratap [this message]
2021-04-26 8:41 ` ep0 request dequeue for function drivers Greg KH
2021-04-26 10:17 ` Felipe Balbi
2021-04-29 8:27 ` Pratham Pratap
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