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| author | Vladis Dronov <vdronov@redhat.com> | 2016-01-31 14:14:52 -0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-11-20 01:17:39 +0000 |
| commit | 25516ba525323b80e7ebed0d0badd6ad169afd21 (patch) | |
| tree | c69d264eb808d45aaefaa67dd72c0f3eda989310 | |
| parent | 8870ad05020ba4bccd21c9bebb4338c5345f084e (diff) | |
| download | lwn-25516ba525323b80e7ebed0d0badd6ad169afd21.tar.gz lwn-25516ba525323b80e7ebed0d0badd6ad169afd21.zip | |
usbvision: revert commit 588afcc1
commit d5468d7afaa9c9e961e150f0455a14a9f4872a98 upstream.
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>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/media/usb/usbvision/usbvision-video.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c index 0dd73a9caf32..354f5a7ae887 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -1537,13 +1537,6 @@ 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) |