CVE-2025-39875: igb: Fix NULL pointer dereference in ethtool loopback test

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-23 · updated 2026-10-19
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: igb: Fix NULL pointer dereference in ethtool loopback test The igb driver currently causes a NULL pointer dereference when executing the ethtool loopback test. This occurs because there is no associated q_vector for the test ring when it is set up, as interrupts are typically not added to the test rings. Since commit 5ef44b3cb43b removed the napi_id assignment in __xdp_rxq_info_reg(), there is no longer a need to pass a napi_id to it. Therefore, simply use 0 as the last parameter.

Affected products

Linux kernel: from 6.14 before 6.16.8; 6.17-rc1, 6.17-rc2, 6.17-rc3, 6.17-rc4, 6.17-rc5 — fixed in 6.16.8

How to fix

Upgrade to a fixed version: Linux kernel 6.16.8. Check the vendor advisory for mitigations.

References

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