CVE-2021-47293

In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_skbmod: Skip non-Ethernet packets Currently tcf_skbmod_act()
assumes that packets use Ethernet as their L2 protocol, which is not always
the case. As an example, for CAN devices: $ ip link add dev vcan0 type vcan
$ ip link set up vcan0 $ tc qdisc add dev vcan0 root handle 1: htb $ tc
filter add dev vcan0 parent 1: protocol ip prio 10 \ matchall action skbmod
swap mac Doing the above silently corrupts all the packets. Do not perform
skbmod actions for non-Ethernet packets.