CVE-2022-49339: In the Linux kernel, the following vulnerability has been resolved: net: ipv6: unexport __init-annotated seg6_hmac_init() EXPORT_SYMBOL and __init i...

Description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: unexport __init-annotated seg6_hmac_init() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because the caller (net/ipv6/seg6.c) and the callee (net/ipv6/seg6_hmac.c) belong to the same module. It seems an internal function call in ipv6.ko.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.26%

17.6th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 4.10, < 4.14.283	—
Linux	Linux Kernel	>= 4.15, < 4.19.247	—
Linux	Linux Kernel	>= 4.20, < 5.4.198	—
Linux	Linux Kernel	>= 5.5, < 5.10.122	—
Linux	Linux Kernel	>= 5.11, < 5.15.47	—
Linux	Linux Kernel	>= 5.16, < 5.17.15	—
Linux	Linux Kernel	>= 5.18, < 5.18.4	—
Linux	Linux Kernel	5.19	Rc1

References

Timeline

Published: Feb 26, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2022-49339?

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: unexport __init-annotated seg6_hmac_init() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because the caller (net/ipv6/seg6.c) and the callee (net/ipv6/seg6_hmac.c) belong to the same module. It seems an internal function call in ipv6.ko.

How severe is CVE-2022-49339?

CVE-2022-49339 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2022-49339?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.