From 772703cadb1bf378bcd5ae87db4c150da37351b6 Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Thu, 31 Mar 2016 10:53:42 -0700 Subject: [PATCH] Input: gtco - fix crash on detecting device without endpoints commit 162f98dea487206d9ab79fc12ed64700667a894d upstream. 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 Signed-off-by: Dmitry Torokhov Signed-off-by: Ben Hutchings --- 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 858045694e9d7..a51de543a0b2f 100644 --- a/drivers/input/tablet/gtco.c +++ b/drivers/input/tablet/gtco.c @@ -868,6 +868,14 @@ 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 @@ -889,7 +897,7 @@ 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; -- 2.47.3