CVE-2025-21808: net: xdp: Disallow attaching device-bound programs in generic mode

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-27 · updated 2026-10-15

Description

In the Linux kernel, the following vulnerability has been resolved: net: xdp: Disallow attaching device-bound programs in generic mode Device-bound programs are used to support RX metadata kfuncs. These kfuncs are driver-specific and rely on the driver context to read the metadata. This means they can't work in generic XDP mode. However, there is no check to disallow such programs from being attached in generic mode, in which case the metadata kfuncs will be called in an invalid context, leading to crashes. Fix this by adding a check to disallow attaching device-bound programs in generic mode.

Affected products

Linux kernel: from 6.3 before 6.6.76; from 6.7 before 6.12.13; from 6.13 before 6.13.2 — fixed in 6.12.13, 6.13.2, 6.6.76

How to fix

Upgrade to a fixed version: Linux kernel 6.12.13, 6.13.2, 6.6.76. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-21808 or the next vulnerability affects your stack