HID: Fix assumption that devices have inputs
commit d9d4b1e46d9543a82c23f6df03f4ad697dab361b upstream.
The syzbot fuzzer found a slab-out-of-bounds write bug in the hid-gaff
driver. The problem is caused by the driver's assumption that the
device must have an input report. While this will be true for all
normal HID input devices, a suitably malicious device can violate the
assumption.
The same assumption is present in over a dozen other HID drivers.
This patch fixes them by checking that the list of hid_inputs for the
hid_device is nonempty before allowing it to be used.
Reported-and-tested-by: syzbot+403741a091bf41d4ae79@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index eee58d1..9633d7a 100644
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -2008,9 +2008,15 @@ static int sony_play_effect(struct input_dev *dev, void *data,
static int sony_init_ff(struct sony_sc *sc)
{
- struct hid_input *hidinput = list_entry(sc->hdev->inputs.next,
- struct hid_input, list);
- struct input_dev *input_dev = hidinput->input;
+ struct hid_input *hidinput;
+ struct input_dev *input_dev;
+
+ if (list_empty(&sc->hdev->inputs)) {
+ hid_err(sc->hdev, "no inputs found\n");
+ return -ENODEV;
+ }
+ hidinput = list_entry(sc->hdev->inputs.next, struct hid_input, list);
+ input_dev = hidinput->input;
input_set_capability(input_dev, EV_FF, FF_RUMBLE);
return input_ff_create_memless(input_dev, NULL, sony_play_effect);