CVE-2025-39853: i40e: Fix potential invalid access when MAC list is empty

Severity: high (CVSS 7.1 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: 2025-09-19 · updated 2026-10-19
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix potential invalid access when MAC list is empty list_first_entry() never returns NULL - if the list is empty, it still returns a pointer to an invalid object, leading to potential invalid memory access when dereferenced. Fix this by using list_first_entry_or_null instead of list_first_entry.

Affected products

Debian Linux: 11.0
Linux kernel: from 4.6 before 5.4.299; from 5.5 before 5.10.243; from 5.11 before 5.15.192; from 5.16 before 6.1.151; from 6.2 before 6.6.105; from 6.7 before 6.12.46 — fixed in 5.10.243, 5.15.192, 5.4.299, 6.1.151, 6.12.46, 6.16.6

How to fix

Upgrade to a fixed version: Linux kernel 5.10.243, 5.15.192, 5.4.299, 6.1.151. Check the vendor advisory for mitigations.

References

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