Ensure, as the driver probes the device, that all endpoints that the driver may attempt to access exist and are of the correct type. All XillyUSB devices must have a Bulk IN and Bulk OUT endpoint at address 1. This is verified in xillyusb_setup_base_eps(). On top of that, a XillyUSB device may have additional Bulk OUT endpoints. The information about these endpoints' addresses is deduced from a data structure (the IDT) that the driver fetches from the device while probing it. These endpoints are checked in setup_channels(). A XillyUSB device never has more than one IN endpoint, as all data towards the host is multiplexed in this single Bulk IN endpoint. This is why setup_channels() only checks OUT endpoints. Reported-by: syzbot+eac39cba052f2e750dbe@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://lore.kernel.org/all/0000000000001d44a6061f7a54ee@xxxxxxxxxx/T/ Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)"). Signed-off-by: Eli Billauer <eli.billauer@xxxxxxxxx> --- drivers/char/xillybus/xillyusb.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/char/xillybus/xillyusb.c b/drivers/char/xillybus/xillyusb.c index e12d359194f8..45771b1a3716 100644 --- a/drivers/char/xillybus/xillyusb.c +++ b/drivers/char/xillybus/xillyusb.c @@ -1903,6 +1903,13 @@ static const struct file_operations xillyusb_fops = { static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev) { + struct usb_device *udev = xdev->udev; + + /* Verify that device has the two fundamental bulk in/out endpoints */ + if (usb_pipe_type_check(udev, usb_sndbulkpipe(udev, MSG_EP_NUM)) || + usb_pipe_type_check(udev, usb_rcvbulkpipe(udev, IN_EP_NUM))) + return -ENODEV; + xdev->msg_ep = endpoint_alloc(xdev, MSG_EP_NUM | USB_DIR_OUT, bulk_out_work, 1, 2); if (!xdev->msg_ep) @@ -1932,14 +1939,15 @@ static int setup_channels(struct xillyusb_dev *xdev, __le16 *chandesc, int num_channels) { - struct xillyusb_channel *chan; + struct usb_device *udev = xdev->udev; + struct xillyusb_channel *chan, *new_channels; int i; chan = kcalloc(num_channels, sizeof(*chan), GFP_KERNEL); if (!chan) return -ENOMEM; - xdev->channels = chan; + new_channels = chan; for (i = 0; i < num_channels; i++, chan++) { unsigned int in_desc = le16_to_cpu(*chandesc++); @@ -1968,6 +1976,15 @@ static int setup_channels(struct xillyusb_dev *xdev, */ if ((out_desc & 0x80) && i < 14) { /* Entry is valid */ + if (usb_pipe_type_check(udev, + usb_sndbulkpipe(udev, i + 2))) { + dev_err(xdev->dev, + "Missing BULK OUT endpoint %d\n", + i + 2); + kfree(new_channels); + return -ENODEV; + } + chan->writable = 1; chan->out_synchronous = !!(out_desc & 0x40); chan->out_seekable = !!(out_desc & 0x20); @@ -1977,6 +1994,7 @@ static int setup_channels(struct xillyusb_dev *xdev, } } + xdev->channels = new_channels; return 0; } -- 2.17.1
