6.6-stable review patch. If anyone has any objections, please let me know.
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From: Mathias Nyman mathias.nyman@linux.intel.com
[ Upstream commit e2e2aacf042f52854c92775b7800ba668e0bdfe4 ]
There is a short gap between urb being submitted and actually added to the endpoint queue (linked). If the device is disconnected during this time then usb core is not yet aware of the pending urb, and device may be freed just before xhci_urq_enqueue() continues, dereferencing the freed device.
Freeing the device is protected by the xhci spinlock, so make sure we take and keep the lock while checking that device exists, dereference it, and add the urb to the queue.
Remove the unnecessary URB check, usb core checks it before calling xhci_urb_enqueue()
Suggested-by: Kuen-Han Tsai khtsai@google.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20231201150647.1307406-20-mathias.nyman@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/host/xhci.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 132b76fa7ca6..e39c5ba9b7c7 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1498,24 +1498,7 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag struct urb_priv *urb_priv; int num_tds;
- if (!urb) - return -EINVAL; - ret = xhci_check_args(hcd, urb->dev, urb->ep, - true, true, __func__); - if (ret <= 0) - return ret ? ret : -EINVAL; - - slot_id = urb->dev->slot_id; ep_index = xhci_get_endpoint_index(&urb->ep->desc); - ep_state = &xhci->devs[slot_id]->eps[ep_index].ep_state; - - if (!HCD_HW_ACCESSIBLE(hcd)) - return -ESHUTDOWN; - - if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR) { - xhci_dbg(xhci, "Can't queue urb, port error, link inactive\n"); - return -ENODEV; - }
if (usb_endpoint_xfer_isoc(&urb->ep->desc)) num_tds = urb->number_of_packets; @@ -1554,12 +1537,35 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
spin_lock_irqsave(&xhci->lock, flags);
+ ret = xhci_check_args(hcd, urb->dev, urb->ep, + true, true, __func__); + if (ret <= 0) { + ret = ret ? ret : -EINVAL; + goto free_priv; + } + + slot_id = urb->dev->slot_id; + + if (!HCD_HW_ACCESSIBLE(hcd)) { + ret = -ESHUTDOWN; + goto free_priv; + } + + if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR) { + xhci_dbg(xhci, "Can't queue urb, port error, link inactive\n"); + ret = -ENODEV; + goto free_priv; + } + if (xhci->xhc_state & XHCI_STATE_DYING) { xhci_dbg(xhci, "Ep 0x%x: URB %p submitted for non-responsive xHCI host.\n", urb->ep->desc.bEndpointAddress, urb); ret = -ESHUTDOWN; goto free_priv; } + + ep_state = &xhci->devs[slot_id]->eps[ep_index].ep_state; + if (*ep_state & (EP_GETTING_STREAMS | EP_GETTING_NO_STREAMS)) { xhci_warn(xhci, "WARN: Can't enqueue URB, ep in streams transition state %x\n", *ep_state);