From: Oliver Neukum <oneukum@xxxxxxxx> commit afdcfd3d6fcdeca2735ca8d994c5f2d24a368f0a upstream. At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver. Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Cc: stable <stable@xxxxxxxxxx> Acked-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240709113851.14691-1-oneukum@xxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/usbip/vhci_hcd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -751,6 +751,7 @@ static int vhci_urb_enqueue(struct usb_h * */ if (usb_pipedevice(urb->pipe) == 0) { + struct usb_device *old; __u8 type = usb_pipetype(urb->pipe); struct usb_ctrlrequest *ctrlreq = (struct usb_ctrlrequest *) urb->setup_packet; @@ -761,14 +762,15 @@ static int vhci_urb_enqueue(struct usb_h goto no_need_xmit; } + old = vdev->udev; switch (ctrlreq->bRequest) { case USB_REQ_SET_ADDRESS: /* set_address may come when a device is reset */ dev_info(dev, "SetAddress Request (%d) to port %d\n", ctrlreq->wValue, vdev->rhport); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); spin_lock(&vdev->ud.lock); vdev->ud.status = VDEV_ST_USED; @@ -787,8 +789,8 @@ static int vhci_urb_enqueue(struct usb_h usbip_dbg_vhci_hc( "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n"); - usb_put_dev(vdev->udev); vdev->udev = usb_get_dev(urb->dev); + usb_put_dev(old); goto out; default: @@ -1095,6 +1097,7 @@ static void vhci_shutdown_connection(str static void vhci_device_reset(struct usbip_device *ud) { struct vhci_device *vdev = container_of(ud, struct vhci_device, ud); + struct usb_device *old = vdev->udev; unsigned long flags; spin_lock_irqsave(&ud->lock, flags); @@ -1102,8 +1105,8 @@ static void vhci_device_reset(struct usb vdev->speed = 0; vdev->devid = 0; - usb_put_dev(vdev->udev); vdev->udev = NULL; + usb_put_dev(old); if (ud->tcp_socket) { sockfd_put(ud->tcp_socket); Patches currently in stable-queue which might be from oneukum@xxxxxxxx are queue-4.19/usb-vhci-hcd-do-not-drop-references-before-new-references-are-gained.patch
