Hi,

On Mon, May 21, 2018 at 3:12 AM, William Wu william.wu@rock-chips.com wrote:

The dwc2_get_ls_map() use ttport to reference into the bitmap if we're on a multi_tt hub. But the bitmaps index from 0 to (hub->maxchild - 1), while the ttport index from 1 to hub->maxchild. This will cause invalid memory access when the number of ttport is hub->maxchild.

Without this patch, I can easily meet a Kernel panic issue if connect a low-speed USB mouse with the max port of FE2.1 multi-tt hub (1a40:0201) on rk3288 platform.

Signed-off-by: William Wu william.wu@rock-chips.com

drivers/usb/dwc2/hcd_queue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/hcd_queue.c b/drivers/usb/dwc2/hcd_queue.c index d7c3d6c..9c55d1a 100644 --- a/drivers/usb/dwc2/hcd_queue.c +++ b/drivers/usb/dwc2/hcd_queue.c @@ -383,7 +383,7 @@ static unsigned long *dwc2_get_ls_map(struct dwc2_hsotg *hsotg, /* Get the map and adjust if this is a multi_tt hub */ map = qh->dwc_tt->periodic_bitmaps; if (qh->dwc_tt->usb_tt->multi)

•           map += DWC2_ELEMENTS_PER_LS_BITMAP * qh->ttport;
  

•           map += DWC2_ELEMENTS_PER_LS_BITMAP * (qh->ttport - 1);
  

Oops, thanks for the fix.

Fixes: 9f9f09b048f5 ("usb: dwc2: host: Totally redo the microframe scheduler") Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson dianders@chromium.org

-Doug