This patch fixes a potential NULL pointer dereference arising on non-present/non-initialized xHCI controllers and adds some error handling to xHCI code

Signed-off-by: Sergey Temerkhanov s.temerkhanov@gmail.com Signed-off-by: Radha Mohan Chintakuntla rchintakuntla@cavium.com

---

Changes in v3: - Assign NULL to *controller so it remains that in case of an error

Changes in v2: - Add return value check with setting hccr and hcor to NULL

drivers/usb/host/xhci.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 0b09643..307e1a6 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -199,7 +199,7 @@ int xhci_reset(struct xhci_hcor *hcor) int ret;

/* Halting the Host first */ - debug("// Halt the HC\n"); + debug("// Halt the HC: %p\n", hcor); state = xhci_readl(&hcor->or_usbsts) & STS_HALT; if (!state) { cmd = xhci_readl(&hcor->or_usbcmd); @@ -1064,6 +1064,8 @@ int usb_lowlevel_init(int index, enum usb_init_type init, void **controller) struct xhci_ctrl *ctrl; int ret;

+ *controller = NULL; + if (xhci_hcd_init(index, &hccr, (struct xhci_hcor **)&hcor) != 0) return -ENODEV;

@@ -1077,7 +1079,12 @@ int usb_lowlevel_init(int index, enum usb_init_type init, void **controller)

ret = xhci_lowlevel_init(ctrl);

- *controller = &xhcic[index]; + if (ret) { + ctrl->hccr = NULL; + ctrl->hcor = NULL; + } else { + *controller = &xhcic[index]; + }

return ret; } @@ -1093,9 +1100,11 @@ int usb_lowlevel_stop(int index) { struct xhci_ctrl *ctrl = (xhcic + index);

- xhci_lowlevel_stop(ctrl); - xhci_hcd_stop(index); - xhci_cleanup(ctrl); + if (ctrl->hcor) { + xhci_lowlevel_stop(ctrl); + xhci_hcd_stop(index); + xhci_cleanup(ctrl); + }

return 0; }