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usb: Do not re-read descriptors for wired devices in usb_authorize_device()

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This patch modifies the usb_authorize_device() function such as that it does
not reload the device descriptor for wired devices. The reasons for this
are as follows:

* Some devices dislike the master requesting the descriptor from them twice,
  failing on the usb_get_device_descriptor() call with -ETIMEOUT. Observed this
  on my Pretec 16GB flash drive (4146:ba65).

* Malicious device could send two different descriptors - one before
  authorization, used by userspace to determine whether to authorize it and
  second to be actually used by the kernel when determining which drivers to
  bind.

Signed-off-by: Josef Gajdusek <atx@atx.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Josef Gajdusek 2014-10-09 15:47:54 +02:00 committed by Greg Kroah-Hartman
parent dd3cf17488
commit e50a322e51
1 changed files with 8 additions and 5 deletions
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13
drivers/usb/core/hub.c
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@ -2543,11 +2543,14 @@ int usb_authorize_device(struct usb_device *usb_dev)
"can't autoresume for authorization: %d\n", result);
goto error_autoresume;
}
result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
if (result < 0) {
dev_err(&usb_dev->dev, "can't re-read device descriptor for "
"authorization: %d\n", result);
goto error_device_descriptor;
if (usb_dev->wusb) {
result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
if (result < 0) {
dev_err(&usb_dev->dev, "can't re-read device descriptor for "
"authorization: %d\n", result);
goto error_device_descriptor;
}
}
usb_dev->authorized = 1;