diff options
| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2010-11-23 10:42:22 -0800 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2011-03-13 18:23:42 -0700 |
| commit | d30b2a208108a0b0fdeae7006b8824d9be16ca96 (patch) | |
| tree | 43df86628f31b4ad46d82258c8d8a1a8e88ae625 /drivers/usb/host | |
| parent | 4bbb0ace9a3de8392527e3c87926309d541d3b00 (diff) | |
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>
Diffstat (limited to 'drivers/usb/host')
| -rw-r--r-- | drivers/usb/host/xhci-mem.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 180a2abbc86..71fd8bd287f 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -1803,6 +1803,20 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags) } xhci_dbg(xhci, "Found %u USB 2.0 ports and %u USB 3.0 ports.\n", xhci->num_usb2_ports, xhci->num_usb3_ports); + + /* Place limits on the number of roothub ports so that the hub + * descriptors aren't longer than the USB core will allocate. + */ + if (xhci->num_usb3_ports > 15) { + xhci_dbg(xhci, "Limiting USB 3.0 roothub ports to 15.\n"); + xhci->num_usb3_ports = 15; + } + if (xhci->num_usb2_ports > USB_MAXCHILDREN) { + xhci_dbg(xhci, "Limiting USB 2.0 roothub ports to %u.\n", + USB_MAXCHILDREN); + xhci->num_usb2_ports = USB_MAXCHILDREN; + } + /* * Note we could have all USB 3.0 ports, or all USB 2.0 ports. * Not sure how the USB core will handle a hub with no ports... @@ -1827,6 +1841,8 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags) "addr = %p\n", i, xhci->usb2_ports[port_index]); port_index++; + if (port_index == xhci->num_usb2_ports) + break; } } if (xhci->num_usb3_ports) { @@ -1845,6 +1861,8 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags) "addr = %p\n", i, xhci->usb3_ports[port_index]); port_index++; + if (port_index == xhci->num_usb3_ports) + break; } } return 0; |