Syzbot reported slab-out-of-bounds read in hci_le_adv_report_evt(). The
problem was in missing validaion check.
We should check if data is not malicious and we can read next data block.
If we won't check ptr validness, code can read a way beyond skb->end and
it can cause problems, of course.
Fixes:
e95beb414168 ("Bluetooth: hci_le_adv_report_evt code refactoring")
Reported-and-tested-by: syzbot+e3fcb9c4f3c2a931dc40@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
struct hci_ev_le_advertising_info *ev = ptr;
s8 rssi;
- if (ev->length <= HCI_MAX_AD_LENGTH) {
+ if (ev->length <= HCI_MAX_AD_LENGTH &&
+ ev->data + ev->length <= skb_tail_pointer(skb)) {
rssi = ev->data[ev->length];
process_adv_report(hdev, ev->evt_type, &ev->bdaddr,
ev->bdaddr_type, NULL, 0, rssi,
}
ptr += sizeof(*ev) + ev->length + 1;
+
+ if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) {
+ bt_dev_err(hdev, "Malicious advertising data. Stopping processing");
+ break;
+ }
}
hci_dev_unlock(hdev);