From: Jonathan Bell jonathan@raspberrypi.com
See https://github.com/raspberrypi/linux/issues/3981
Two read-modify-write cycles on ep->ep_state are not guarded by xhci->lock. Fix these.
Signed-off-by: Jonathan Bell jonathan@raspberrypi.com Fixes: f5249461b504 ("xhci: Clear the host side toggle manually when endpoint is soft reset") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 93c38b557afd..541fe4dcc43a 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3214,10 +3214,13 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd, return;
/* Bail out if toggle is already being cleared by a endpoint reset */ + spin_lock_irqsave(&xhci->lock, flags); if (ep->ep_state & EP_HARD_CLEAR_TOGGLE) { ep->ep_state &= ~EP_HARD_CLEAR_TOGGLE; + spin_unlock_irqrestore(&xhci->lock, flags); return; } + spin_unlock_irqrestore(&xhci->lock, flags); /* Only interrupt and bulk ep's use data toggle, USB2 spec 5.5.4-> */ if (usb_endpoint_xfer_control(&host_ep->desc) || usb_endpoint_xfer_isoc(&host_ep->desc)) @@ -3303,8 +3306,10 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd, xhci_free_command(xhci, cfg_cmd); cleanup: xhci_free_command(xhci, stop_cmd); + spin_lock_irqsave(&xhci->lock, flags); if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE) ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE; + spin_unlock_irqrestore(&xhci->lock, flags); }
static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,