CVE-2026-99066

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

can: dev: init can skb(): restore skb header initialization

Commit 9f10374bb024 ("can: remove private CAN skb headroom infrastructure") removed the skb reset mac header()/skb reset network header()/ skb reset transport header() calls from init can skb(). As a result, RX skbs from alloc can skb() and friends again carry mac header = 0xFFFF. When such an skb reaches packet rcv spkt() (SOCK PACKET), the push length calculation overflows and triggers skb under panic -> kernel BUG -> full machine panic.

The same issue was originally reported in 2014 on linux-can and fixed by commit 969439016d2c ("can: add missing initialisations in CAN related skbuffs"). packet rcv spkt() itself has never been hardened: only packet rcv() and tpacket rcv() gained dev has header() checks in commit d549699048b4 ("net/packet: fix packet receive on L3 devices without visible hard header").