[PATCH 4.19 18/85] HID: holtek: test for sanity of intfdata

Greg Kroah-Hartman
2019-08-22T17:29:14Z

From: Oliver Neukum <oneukum@suse.com>

commit 01ec0a5f19c8c82960a07f6c7410fc9e01d7fb51 upstream.

The ioctl handler uses the intfdata of a second interface,
which may not be present in a broken or malicious device, hence
the intfdata needs to be checked for NULL.

[jkosina@suse.cz: fix newly added spurious space]
Reported-by: syzbot+965152643a75a56737be@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hid/hid-holtek-kbd.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/hid/hid-holtek-kbd.c
+++ b/drivers/hid/hid-holtek-kbd.c
@@ -126,9 +126,14 @@ static int holtek_kbd_input_event(struct

/* Locate the boot interface, to receive the LED change events */
struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0);
+ struct hid_device *boot_hid;
+ struct hid_input *boot_hid_input;

- struct hid_device *boot_hid = usb_get_intfdata(boot_interface);
- struct hid_input *boot_hid_input = list_first_entry(&boot_hid->inputs,
+ if (unlikely(boot_interface == NULL))
+ return -ENODEV;
+
+ boot_hid = usb_get_intfdata(boot_interface);
+ boot_hid_input = list_first_entry(&boot_hid->inputs,
struct hid_input, list);

return boot_hid_input->input->event(boot_hid_input->input, type, code,