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

macvlan: enforce a consistent minimal mtu

macvlan should enforce a minimal mtu of 68, even at link creation.

This patch avoids the current behavior (which could lead to crashes
in ipv6 stack if the link is brought up)

$ ip link add macvlan1 link eno1 mtu 8 type macvlan  # This should fail !
$ ip link sh dev macvlan1
5: macvlan1@eno1: <BROADCAST,MULTICAST> mtu 8 qdisc noop
    state DOWN mode DEFAULT group default qlen 1000
    link/ether 02:47:6c:24:74:82 brd ff:ff:ff:ff:ff:ff
$ ip link set macvlan1 mtu 67
Error: mtu less than device minimum.
$ ip link set macvlan1 mtu 68
$ ip link set macvlan1 mtu 8
Error: mtu less than device minimum.

https://git.kernel.org/stable/c/2b055c719d8f94c15ec9b7659978133030c6a353

https://git.kernel.org/stable/c/650137a7c0b2892df2e5b0bc112d7b09a78c93c8

https://git.kernel.org/stable/c/a62aa84fe19eb24d083d600a074c009a0a66d4f3

https://git.kernel.org/stable/c/b64085b00044bdf3cd1c9825e9ef5b2e0feae91a

https://git.kernel.org/stable/c/d2fee7d121d189c6dc905b727d60e7043a6655bb

https://git.kernel.org/stable/c/e41cbf98df22d08402e65174d147cbb187fe1a33

https://git.kernel.org/stable/c/e929ec98c0c3b10d9c07f3776df0c1a02d7a763e