diff options
| author | Douglas Anderson <dianders@chromium.org> | 2023-12-11 07:32:41 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-12-15 13:54:09 +0100 |
| commit | 44995e6f07028f798efd0c3c11a1efc78330f600 (patch) | |
| tree | c20cf4e961f2e5d575b4615caa14fc0fa556ff3b /drivers/usb/core | |
| parent | 7d530f4cc0632056d9f8f207245aa3d91a25d168 (diff) | |
usb: core: Fix crash w/ usb_choose_configuration() if no driver
It's possible that usb_choose_configuration() can get called when a
USB device has no driver. In this case the recent commit a87b8e3be926
("usb: core: Allow subclassed USB drivers to override
usb_choose_configuration()") can cause a crash since it dereferenced
the driver structure without checking for NULL. Let's add a check.
A USB device with no driver is an anomaly, so make
usb_choose_configuration() return immediately if there is no driver.
This was seen in the real world when usbguard got ahold of a r8152
device at the wrong time. It can also be simulated via this on a
computer with one r8152-based USB Ethernet adapter:
cd /sys/bus/usb/drivers/r8152-cfgselector
to_unbind="$(ls -d *-*)"
real_dir="$(readlink -f "${to_unbind}")"
echo "${to_unbind}" > unbind
cd "${real_dir}"
echo 0 > authorized
echo 1 > authorized
Fixes: a87b8e3be926 ("usb: core: Allow subclassed USB drivers to override usb_choose_configuration()")
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20231211073237.v3.1.If27eb3bf7812f91ab83810f232292f032f4203e0@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/generic.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index dcb897158228..b134bff5c3fe 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -59,7 +59,16 @@ int usb_choose_configuration(struct usb_device *udev) int num_configs; int insufficient_power = 0; struct usb_host_config *c, *best; - struct usb_device_driver *udriver = to_usb_device_driver(udev->dev.driver); + struct usb_device_driver *udriver; + + /* + * If a USB device (not an interface) doesn't have a driver then the + * kernel has no business trying to select or install a configuration + * for it. + */ + if (!udev->dev.driver) + return -1; + udriver = to_usb_device_driver(udev->dev.driver); if (usb_device_is_owned(udev)) return 0; |