On Tue, 21 Jul 2015, Peter Chen wrote: > The ehci_init_driver is used to initialize hcd APIs for each > ehci controller driver, it is designed to be called only one time > and before driver register is called. The current design will > cause ehci_init_driver is called multiple times at probe process, > it will cause hc_driver's initialization affect current running hcd. > > We run out NULL pointer dereference problem when one hcd is started > by module_init, and the other is started by otg thread at SMP platform. > The reason for this problem is ehci_init_driver will do memory copy > for current uniform hc_driver, and this memory copy will do memset (as 0) > first, so when the first hcd is running usb_add_hcd, and the second > hcd may clear the uniform hc_driver's space (at ehci_init_driver), > then the first hcd will meet NULL pointer at the same time. > Cc: Jun Li <jun.li@xxxxxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html