On 8/24/21 6:07 PM, F.A.Sulaiman wrote:
Syzbot reported slab-out-of-bounds Write bug in hid-betopff driver. The problem is the driver assumes the device must have an input report but some malicious devices violate this assumption. So this patch checks hid_device's input is non empty before it's been used. Reported-by: syzbot+07efed3bc5a1407bd742@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: F.A. SULAIMAN <asha.16@xxxxxxxxxxxxxxx>
Reviewed-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
--- drivers/hid/hid-betopff.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-betopff.c b/drivers/hid/hid-betopff.c index 0790fbd3fc9a..467d789f9bc2 100644 --- a/drivers/hid/hid-betopff.c +++ b/drivers/hid/hid-betopff.c @@ -56,15 +56,22 @@ static int betopff_init(struct hid_device *hid) { struct betopff_device *betopff; struct hid_report *report; - struct hid_input *hidinput = - list_first_entry(&hid->inputs, struct hid_input, list); + struct hid_input *hidinput; struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list; - struct input_dev *dev = hidinput->input; + struct input_dev *dev; int field_count = 0; int error; int i, j;+ if (list_empty(&hid->inputs)) {+ hid_err(hid, "no inputs found\n"); + return -ENODEV; + } + + hidinput = list_first_entry(&hid->inputs, struct hid_input, list); + dev = hidinput->input; + if (list_empty(report_list)) { hid_err(hid, "no output reports found\n"); return -ENODEV;
