In the Linux kernel, the following vulnerability has been resolved: net: add more sanity checks to qdiscpktleninit() One path takes care of SKBGSODODGY, assuming skb->len is bigger than hdrlen. virtionethdrtoskb() does not fully dissect TCP headers, it only make sure it is at least 20 bytes. It is possible for an user to provide a malicious 'GSO' packet, total length of 80 bytes. - 20 bytes of IPv4 header - 60 bytes TCP header - a small gsosize like 8 virtionethdrtoskb() would declare this packet as a normal GSO packet, because it would see 40 bytes of payload, bigger than gsosize. We need to make detect this case to not underflow qdiscskbcb(skb)->pkt_len.