CVE-2025-22063: netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-16 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets When calling netlbl_conn_setattr(), addr->sa_family is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipso_sock_setattr() is triggered. Inside this function, the following code is executed: sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL; Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference. This patch fixes the issue by checking if inet6_sk(sk) returns a NULL pointer before accessing pinet6.

Affected products

Linux kernel: from 4.8 before 5.4.292; from 5.5 before 5.10.236; from 5.11 before 5.15.180; from 5.16 before 6.1.134; from 6.2 before 6.6.87; from 6.7 before 6.12.23 — fixed in 5.10.236, 5.15.180, 5.4.292, 6.1.134, 6.12.23, 6.13.11

How to fix

Upgrade to a fixed version: Linux kernel 5.10.236, 5.15.180, 5.4.292, 6.1.134. Check the vendor advisory for mitigations.

References

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