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Unrated severityNVD Advisory· Published May 21, 2024· Updated May 4, 2025

net/sched: act_skbmod: Skip non-Ethernet packets

CVE-2021-47293

Description

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.

Affected products

24

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

5

News mentions

0

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