From: F.A.Sulaiman asha.16@itfac.mrt.ac.lk
commit 1e4ce418b1cb1a810256b5fb3fd33d22d1325993 upstream.
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@syzkaller.appspotmail.com Signed-off-by: F.A. SULAIMAN asha.16@itfac.mrt.ac.lk Reviewed-by: Pavel Skripkin paskripkin@gmail.com Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hid/hid-betopff.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/hid/hid-betopff.c +++ b/drivers/hid/hid-betopff.c @@ -56,15 +56,22 @@ static int betopff_init(struct hid_devic { 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;