xhci: Limit roothub ports to 15 USB3 & 31 USB2 ports.
The USB core allocates a USB 2.0 roothub descriptor that has room for 31 (USB_MAXCHILDREN) ports' worth of DeviceRemovable and PortPwrCtrlMask fields. Limit the number of USB 2.0 roothub ports accordingly. I don't expect to run into this limitation ever, but this prevents a buffer overflow issue in the roothub descriptor filling code. Similarly, a USB 3.0 hub can only have 15 downstream ports, so limit the USB 3.0 roothub to 15 USB 3.0 ports. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
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@ -1803,6 +1803,20 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
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}
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xhci_dbg(xhci, "Found %u USB 2.0 ports and %u USB 3.0 ports.\n",
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xhci->num_usb2_ports, xhci->num_usb3_ports);
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/* Place limits on the number of roothub ports so that the hub
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* descriptors aren't longer than the USB core will allocate.
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*/
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if (xhci->num_usb3_ports > 15) {
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xhci_dbg(xhci, "Limiting USB 3.0 roothub ports to 15.\n");
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xhci->num_usb3_ports = 15;
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}
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if (xhci->num_usb2_ports > USB_MAXCHILDREN) {
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xhci_dbg(xhci, "Limiting USB 2.0 roothub ports to %u.\n",
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USB_MAXCHILDREN);
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xhci->num_usb2_ports = USB_MAXCHILDREN;
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}
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/*
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* Note we could have all USB 3.0 ports, or all USB 2.0 ports.
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* Not sure how the USB core will handle a hub with no ports...
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@ -1827,6 +1841,8 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
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"addr = %p\n", i,
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xhci->usb2_ports[port_index]);
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port_index++;
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if (port_index == xhci->num_usb2_ports)
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break;
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}
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}
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if (xhci->num_usb3_ports) {
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@ -1845,6 +1861,8 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
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"addr = %p\n", i,
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xhci->usb3_ports[port_index]);
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port_index++;
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if (port_index == xhci->num_usb3_ports)
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break;
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}
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}
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return 0;
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