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From: Greg KH <gregkh@linuxfoundation.org>
To: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Cc: linux-usb@vger.kernel.org, robh@kernel.org,
	p.zabel@pengutronix.de, stern@rowland.harvard.edu, arnd@arndb.de,
	peter.chen@freescale.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: core: of: Check device_node before parsing in usb_of_get_child_node()
Date: Mon, 15 Aug 2016 20:41:17 +0200	[thread overview]
Message-ID: <20160815184117.GA883@kroah.com> (raw)
In-Reply-To: <1471285870-21433-1-git-send-email-vaibhav.hiremath@linaro.org>

On Mon, Aug 15, 2016 at 11:31:10AM -0700, Vaibhav Hiremath wrote:
> In case of HUB devices connected to USB ports, we may not have DT
> node representing it inside USB, and when devices connected to hub
> gets enumerated, call to usb_of_get_child_node() leads to NULL pointer
> dereference.

Really?  That seems messed up.

> In the usecase we have, where EHCI port is connected to USB HUB
> device, and downward ports of HUB are connected to further USB
> devices. When those devices gets enumerated, in order,
>  1. USB HUB ->
> 	-> Call to usb_of_get_child_node() is OK, as
> 	parent->dev.of_node is pointing to host node.
>  2. Devices connected to downward port of USB HUB
>  	-> Call to usb_of_get_child_node() leads to NULL
> 	pointer dereference as parent->dev.of_node = NULL,
> 	as USB HUB DTS node may be empty.

Why is the hub DTS empty?  Shouldn't that be the fix here?

thanks,

greg k-h

  reply	other threads:[~2016-08-15 18:41 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-15 18:31 [PATCH] USB: core: of: Check device_node before parsing in usb_of_get_child_node() Vaibhav Hiremath
2016-08-15 18:41 ` Greg KH [this message]
2016-08-15 19:18   ` Vaibhav Hiremath
2016-08-15 19:34   ` Alan Stern
2016-08-16  1:33 ` Peter Chen
2016-08-16 21:14   ` Vaibhav Hiremath

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