CVE-2024-27431: cpumap: Zero-initialise xdp_rxq_info struct before running XDP program

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: 2024-05-17 · updated 2026-10-15
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: cpumap: Zero-initialise xdp_rxq_info struct before running XDP program When running an XDP program that is attached to a cpumap entry, we don't initialise the xdp_rxq_info data structure being used in the xdp_buff that backs the XDP program invocation. Tobias noticed that this leads to random values being returned as the xdp_md->rx_queue_index value for XDP programs running in a cpumap. This means we're basically returning the contents of the uninitialised memory, which is bad. Fix this by zero-initialising the rxq data structure before running the XDP program.

Affected products

Debian Linux: 10.0
Linux kernel: from 5.9 before 5.10.213; from 5.11 before 5.15.152; from 5.16 before 6.1.82; from 6.2 before 6.6.22; from 6.7 before 6.7.10; 6.8-rc1, 6.8-rc2, 6.8-rc3, 6.8-rc4, 6.8-rc5, 6.8-rc6 (+1) — fixed in 5.10.213, 5.15.152, 6.1.82, 6.6.22, 6.7.10

How to fix

Upgrade to a fixed version: Linux kernel 5.10.213, 5.15.152, 6.1.82, 6.6.22. Check the vendor advisory for mitigations.

References

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