From: Anton Vasilyev <vasilyev@ispras.ru>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jussi Kivilinna <jussi.kivilinna@haltian.com>,
Peter Senna Tschudin <peter.senna@collabora.com>,
Raz Manor <Raz.Manor@valens.com>,
Romain Perier <romain.perier@collabora.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
ldv-project@linuxtesting.org
Subject: Re: [PATCH] udc: Memory leak on error path and use after free
Date: Wed, 16 Aug 2017 19:00:05 +0300 [thread overview]
Message-ID: <682044ba-e4c2-a1b9-3652-a01e81a40ac2@ispras.ru> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1708161125520.3053-100000@iolanthe.rowland.org>
On 16.08.2017 18:29, Alan Stern wrote:
> 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?
>
No, this situation could appear before call
usb_add_gadget_udc_release().
>> 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?
>
net2280_remove() continue work with struct net2280 *dev after call
usb_del_gadget_udc(&dev->gadget), but this net2280 *dev could be
deallocated by gadget_release()
>> The patch moves deallocation from gadget_release() to
>> net2280_remove().
>
> Alan Stern
>
--
Anton Vasilyev
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: vasilyev@ispras.ru
next prev parent reply other threads:[~2017-08-16 16:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-16 13:47 Anton Vasilyev
2017-08-16 15:29 ` Alan Stern
2017-08-16 16:00 ` Anton Vasilyev [this message]
2017-08-16 16:35 ` Alan Stern
2017-08-22 15:45 ` Anton Vasilyev
2017-08-22 18:37 ` Alan Stern
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