In the Linux kernel, the following vulnerability has been resolved:
fou: Don't allow 0 for FOU_ATTR_IPPROTO.
fou_udp_recv() has the same problem mentioned in the previous patch.
If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu().
Let's forbid 0 for FOU_ATTR_IPPROTO.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H