4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit d5468d7afaa9c9e961e150f0455a14a9f4872a98 ]
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 vdronov@redhat.com Signed-off-by: Hans Verkuil hans.verkuil@cisco.com Cc: stable@vger.kernel.org # for v4.5 Signed-off-by: Mauro Carvalho Chehab mchehab@osg.samsung.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 cafc34938a79..91d709efef7a 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -1461,13 +1461,6 @@ 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)