From: Johan Hovold <johan@kernel.org> commit bcfcb7f9b480dd0be8f0df2df17340ca92a03b98 upstream. The driver was checking the number of endpoints of the first alternate setting instead of the current one, something which could be used by a malicious device (or USB descriptor fuzzer) to trigger a NULL-pointer dereference. Fixes: 1afca2b66aac ("Input: add Pegasus Notetaker tablet driver") Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Martin Kepplinger <martink@posteo.de> Acked-by: Vladis Dronov <vdronov@redhat.com> Link: https://lore.kernel.org/r/20191210113737.4016-2-johan@kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/input/tablet/pegasus_notetaker.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c index ffd03cf..570cdae 100644 --- a/drivers/input/tablet/pegasus_notetaker.c +++ b/drivers/input/tablet/pegasus_notetaker.c @@ -274,7 +274,7 @@ static int pegasus_probe(struct usb_interface *intf, return -ENODEV; /* Sanity check that the device has an endpoint */ - if (intf->altsetting[0].desc.bNumEndpoints < 1) { + if (intf->cur_altsetting->desc.bNumEndpoints < 1) { dev_err(&intf->dev, "Invalid number of endpoints\n"); return -EINVAL; } -- 1.8.3