From 9d51ba9909129465493d56a7134ce4220d2e69e9 Mon Sep 17 00:00:00 2001 From: Jonathan Bell Date: Mon, 16 Aug 2021 14:43:06 +0100 Subject: [PATCH] xhci: guard accesses to ep_state in xhci_endpoint_reset() 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 --- drivers/usb/host/xhci.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3270,10 +3270,13 @@ static void xhci_endpoint_reset(struct u 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)) @@ -3359,8 +3362,10 @@ static void xhci_endpoint_reset(struct u 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,