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...