On Tue, 26 Feb 2013, Daniel J Blueman wrote:
> When initialisation of one or more USB hub ports fails, we can hit a null
> pointer dereference when dropping the hub. Analysis shows there's a false
> assumption about the ports being setup, so address this.
> Signed-off-by: Daniel J Blueman <dan...@numascale-asia.com>
> ---
> drivers/usb/core/hub.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index cbf7168..a7abc57 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1263,7 +1263,7 @@ static void hub_quiesce(struct usb_hub *hub, enum
> hub_quiescing_type type)
> if (type != HUB_SUSPEND) {
> /* Disconnect all the children */
> for (i = 0; i < hdev->maxchild; ++i) {
> - if (hub->ports[i]->child)
> + if (hub->ports[i] && hub->ports[i]->child)
> usb_disconnect(&hub->ports[i]->child);
> }
> }
You missed a case. What happens if hub->ports is NULL?
Also, what about this code in hub_disconnect?
for (i = 0; i < hdev->maxchild; i++)
usb_hub_remove_port_device(hub, i + 1);
All of these problems can be fixed in hub_configure by setting
hub->maxchild to the total number of allocated ports (or 0 if hub_ports
can't be allocated).
Alan Stern
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