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.

• linux linux kernel (>= 4.9 < 4.19.199) • linux linux kernel (>= 4.20 < 5.4.136) • linux linux kernel (>= 5.5 < 5.10.54) • linux linux kernel (>= 5.11 < 5.13.6) • linux linux kernel 5.14