CVE-2021-46991: i40e: Fix use-after-free in i40e_client_subtask()

Severity: high (CVSS 7.8 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: 2024-02-28 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix use-after-free in i40e_client_subtask() Currently the call to i40e_client_del_instance frees the object pf->cinst, however pf->cinst->lan_info is being accessed after the free. Fix this by adding the missing return. Addresses-Coverity: ("Read from pointer after free")

Affected products

Linux kernel: from 4.16 before 4.19.191; from 4.20 before 5.4.120; from 5.5 before 5.10.38; from 5.11 before 5.11.22; from 5.12 before 5.12.5 — fixed in 4.19.191, 5.10.38, 5.11.22, 5.12.5, 5.4.120

How to fix

Upgrade to a fixed version: Linux kernel 4.19.191, 5.10.38, 5.11.22, 5.12.5. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-46991 or the next vulnerability affects your stack