diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 61f48b17e57b6688599e9269c6933cfeb51fdf92..0420eefa647a15cb5321dfa5fd95556a5a5432e5 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -37,6 +37,21 @@ static unsigned long long quirks; module_param(quirks, ullong, S_IRUGO); MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default"); +static bool td_on_ring(struct xhci_td *td, struct xhci_ring *ring) +{ + struct xhci_segment *seg = ring->first_seg; + + if (!td || !td->start_seg) + return false; + do { + if (seg == td->start_seg) + return true; + seg = seg->next; + } while (seg && seg != ring->first_seg); + + return false; +} + /* TODO: copied from ehci-hcd.c - can this be refactored? */ /* * xhci_handshake - spin reading hc until handshake completes or fails @@ -1571,6 +1586,21 @@ static int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) goto done; } + /* + * check ring is not re-allocated since URB was enqueued. If it is, then + * make sure none of the ring related pointers in this URB private data + * are touched, such as td_list, otherwise we overwrite freed data + */ + if (!td_on_ring(&urb_priv->td[0], ep_ring)) { + xhci_err(xhci, "Canceled URB td not found on endpoint ring"); + for (i = urb_priv->num_tds_done; i < urb_priv->num_tds; i++) { + td = &urb_priv->td[i]; + if (!list_empty(&td->cancelled_td_list)) + list_del_init(&td->cancelled_td_list); + } + goto err_giveback; + } + if (xhci->xhc_state & XHCI_STATE_HALTED) { xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb, "HC halted, freeing TD manually.");