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Date:   Tue, 25 Aug 2020 10:39:46 -0400
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Himadri Pandya <himadrispandya@gmail.com>,
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        Jakub Kicinski <kuba@kernel.org>,
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Subject: Re: [PATCH] net: usb: Fix uninit-was-stored issue in asix_read_cmd()
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On Tue, Aug 25, 2020 at 08:51:35AM +0200, Greg Kroah-Hartman wrote:
> At first glance, I think this can all be cleaned up, but it will take a
> bit of tree-wide work.  I agree, we need a "read this message and error
> if the whole thing is not there", as well as a "send this message and
> error if the whole thing was not sent", and also a way to handle
> stack-provided data, which seems to be the primary reason subsystems
> wrap this call (they want to make it easier on their drivers to use it.)
> 
> Let me think about this in more detail, but maybe something like:
> 	usb_control_msg_read()
> 	usb_control_msg_send()
> is a good first step (as the caller knows this) and stack provided data
> would be allowed, and it would return an error if the whole message was
> not read/sent properly.  That way we can start converting everything
> over to a sane, and checkable, api and remove a bunch of wrapper
> functions as well.

Suggestion: _read and _send are not a natural pair.  Consider instead
_read and _write.  _recv and _send don't feel right either, because it
both cases the host sends the control message -- the difference lies
in who sends the data.

Alan Stern