This is a note to let you know that I've just added the patch titled
HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hid-lenovo-check-hid_get_drvdata-returns-non-null-in.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 66ce38973cf971681355ef9883218cdaeb4ed1ea
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sun Apr 4 10:04:26 2021 +0200
HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event()
[ Upstream commit 34348a8661e3cd67dcf6938f08c8bb77522301f7 ]
The HID lenovo probe function only attaches drvdata to one of the
USB interfaces, but lenovo_event() will get called for all USB interfaces
to which hid-lenovo is bound.
This allows a malicious device to fake being a device handled by
hid-lenovo, which generates events for which lenovo_event() has
special handling (and thus dereferences hid_get_drvdata()) on another
interface triggering a NULL pointer exception.
Add a check for hid_get_drvdata() returning NULL, avoiding this
possible NULL pointer exception.
Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Reviewed-by: Marek Behún <kabel@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index ee175ab54281..b2596ed37880 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -508,6 +508,9 @@ static int lenovo_event_cptkbd(struct hid_device *hdev,
static int lenovo_event(struct hid_device *hdev, struct hid_field *field,
struct hid_usage *usage, __s32 value)
{
+ if (!hid_get_drvdata(hdev))
+ return 0;
+
switch (hdev->product) {
case USB_DEVICE_ID_LENOVO_CUSBKBD:
case USB_DEVICE_ID_LENOVO_CBTKBD:
