CVE-2025-38112: net: Fix TOCTOU issue in sk_is_readable()

Severity: medium (CVSS 4.7 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: 2025-07-03 · updated 2026-06-17
Weakness: CWE-367

Description

In the Linux kernel, the following vulnerability has been resolved: net: Fix TOCTOU issue in sk_is_readable() sk->sk_prot->sock_is_readable is a valid function pointer when sk resides in a sockmap. After the last sk_psock_put() (which usually happens when socket is removed from sockmap), sk->sk_prot gets restored and sk->sk_prot->sock_is_readable becomes NULL. This makes sk_is_readable() racy, if the value of sk->sk_prot is reloaded after the initial check. Which in turn may lead to a null pointer dereference. Ensure the function pointer does not turn NULL after the check.

Affected products

Debian Linux: 11.0
Linux kernel: from 4.17 before 5.10.239; from 5.11 before 5.15.186; from 5.16 before 6.1.142; from 6.2 before 6.6.94; from 6.7 before 6.12.34; from 6.13 before 6.15.3 — fixed in 5.10.239, 5.15.186, 6.1.142, 6.12.34, 6.15.3, 6.6.94

How to fix

Upgrade to a fixed version: Linux kernel 5.10.239, 5.15.186, 6.1.142, 6.12.34. Check the vendor advisory for mitigations.

References

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