CVE-2024-26804 net: ip_tunnel: prevent perpetual headroom growth

In the Linux kernel, the following vulnerability has been resolved: net: iptunnel: prevent perpetual headroom growth syzkaller triggered following kasan splat: BUG: KASAN: use-after-free in skbflowdissect+0x19d1/0x7a50 net/core/flowdissector.c:1170 Read of size 1 at addr ffff88812fb4000e by task...

CVE-2024-26804

CVE-2024-26804 affects the Linux kernel's IP tunnel infrastructure. The issue arises when packets are routed through a GRE tunnel and then encapsulated again (via ip_tunnel_xmit/ipip_tunnel_xmit), causing gre0 and ipip0 to inflate dev->needed_headroom iteratively. The neigh layer pulls skb wit...