CVE-2024-41091: tun: add missing verification for short frame

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-29 · updated 2026-08-04
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: tun: add missing verification for short frame The cited commit missed to check against the validity of the frame length in the tun_xdp_one() path, which could cause a corrupted skb to be sent downstack. Even before the skb is transmitted, the tun_xdp_one-->eth_type_trans() may access the Ethernet header although it can be less than ETH_HLEN. Once transmitted, this could either cause out-of-bound access beyond the actual length, or confuse the underlayer with incorrect or inconsistent header length in the skb metadata. In the alternative path, tun_get_user() already prohibits short frame which has the length less than Ethernet header size from being transmitted for IFF_TAP. This is to drop any frame shorter than the Ethernet header size just like how tun_get_user() does. CVE: CVE-2024-41091

Affected products

Linux kernel: from 4.20 before 5.4.281; from 5.5 before 5.10.223; from 5.11 before 5.15.164; from 5.16 before 6.1.102; from 6.2 before 6.6.43; from 6.7 before 6.9.12 — fixed in 5.10.223, 5.15.164, 5.4.281, 6.1.102, 6.10.2, 6.6.43

How to fix

Upgrade to a fixed version: Linux kernel 5.10.223, 5.15.164, 5.4.281, 6.1.102. Check the vendor advisory for mitigations.

References

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