CVE-2024-41091: Out-of-bounds Read

In the Linux kernel, the following vulnerability has been resolved:

tun: add missing verification for short frame

The cited commit missed to check against the validity of the frame length in the tun_xdp_one() path, which could cause a corrupted skb to be sent downstack. Even before the skb is transmitted, the tun_xdp_one-->eth_type_trans() may access the Ethernet header although it can be less than ETH_HLEN. Once transmitted, this could either cause out-of-bound access beyond the actual length, or confuse the underlayer with incorrect or inconsistent header length in the skb metadata.

In the alternative path, tun_get_user() already prohibits short frame which has the length less than Ethernet header size from being transmitted for IFF_TAP.

This is to drop any frame shorter than the Ethernet header size just like how tun_get_user() does.

CVE: CVE-2024-41091