From d5468d7afaa9c9e961e150f0455a14a9f4872a98 Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Sun, 31 Jan 2016 14:14:52 -0200 Subject: [PATCH] [media] usbvision: revert commit 588afcc1 Commit 588afcc1c0e4 ("[media] usbvision fix overflow of interfaces array")' should be reverted, because: * "!dev->actconfig->interface[ifnum]" won't catch a case where the value is not NULL but some garbage. This way the system may crash later with GPF. * "(ifnum >= USB_MAXINTERFACES)" does not cover all the error conditions. "ifnum" should be compared to "dev->actconfig-> desc.bNumInterfaces", i.e. compared to the number of "struct usb_interface" kzalloc()-ed, not to USB_MAXINTERFACES. * There is a "struct usb_device" leak in this error path, as there is usb_get_dev(), but no usb_put_dev() on this path. * There is a bug of the same type several lines below with number of endpoints. The code is accessing hard-coded second endpoint ("interface->endpoint[1].desc") which may not exist. It would be great to handle this in the same patch too. * All the concerns above are resolved by already-accepted commit fa52bd50 ("[media] usbvision: fix crash on detecting device with invalid configuration") * Mailing list message: http://www.spinics.net/lists/linux-media/msg94832.html Signed-off-by: Vladis Dronov Signed-off-by: Hans Verkuil Cc: # for v4.5 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/usbvision/usbvision-video.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c index 12f5ebbd0436..ad2f3d27b266 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -1452,13 +1452,6 @@ static int usbvision_probe(struct usb_interface *intf, printk(KERN_INFO "%s: %s found\n", __func__, usbvision_device_data[model].model_string); - /* - * this is a security check. - * an exploit using an incorrect bInterfaceNumber is known - */ - if (ifnum >= USB_MAXINTERFACES || !dev->actconfig->interface[ifnum]) - return -ENODEV; - if (usbvision_device_data[model].interface >= 0) interface = &dev->actconfig->interface[usbvision_device_data[model].interface]->altsetting[0]; else if (ifnum < dev->actconfig->desc.bNumInterfaces) -- 2.20.1