From: Vladis Dronov Date: Thu, 31 Mar 2016 10:53:42 -0700 Subject: Input: gtco - fix crash on detecting device without endpoints Origin: https://git.kernel.org/linus/162f98dea487206d9ab79fc12ed64700667a894d The gtco driver expects at least one valid endpoint. If given malicious descriptors that specify 0 for the number of endpoints, it will crash in the probe function. Ensure there is at least one endpoint on the interface before using it. Also let's fix a minor coding style issue. The full correct report of this issue can be found in the public Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1283385 Reported-by: Ralf Spenneberg Signed-off-by: Vladis Dronov Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov --- drivers/input/tablet/gtco.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/input/tablet/gtco.c b/drivers/input/tablet/gtco.c index 3a7f3a4a4396..7c18249d6c8e 100644 --- a/drivers/input/tablet/gtco.c +++ b/drivers/input/tablet/gtco.c @@ -858,6 +858,14 @@ static int gtco_probe(struct usb_interface *usbinterface, goto err_free_buf; } + /* Sanity check that a device has an endpoint */ + if (usbinterface->altsetting[0].desc.bNumEndpoints < 1) { + dev_err(&usbinterface->dev, + "Invalid number of endpoints\n"); + error = -EINVAL; + goto err_free_urb; + } + /* * The endpoint is always altsetting 0, we know this since we know * this device only has one interrupt endpoint @@ -879,7 +887,7 @@ static int gtco_probe(struct usb_interface *usbinterface, * HID report descriptor */ if (usb_get_extra_descriptor(usbinterface->cur_altsetting, - HID_DEVICE_TYPE, &hid_desc) != 0){ + HID_DEVICE_TYPE, &hid_desc) != 0) { dev_err(&usbinterface->dev, "Can't retrieve exta USB descriptor to get hid report descriptor length\n"); error = -EIO;