CVE-2024-39503: netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type

Severity: high (CVSS 7.0 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: 2024-07-12 · updated 2026-10-15
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type Lion Ackermann reported that there is a race condition between namespace cleanup in ipset and the garbage collection of the list:set type. The namespace cleanup can destroy the list:set type of sets while the gc of the set type is waiting to run in rcu cleanup. The latter uses data from the destroyed set which thus leads use after free. The patch contains the following parts: - When destroying all sets, first remove the garbage collectors, then wait if needed and then destroy the sets. - Fix the badly ordered "wait then remove gc" for the destroy a single set case. - Fix the missing rcu locking in the list:set type in the userspace test case. - Use proper RCU list handlings in the list:set type. The patch depends on c1193d9bbbd3 (netfilter: ipset: Add list flush to cancel_gc).

Affected products

Linux kernel: from 5.4.269 before 5.4.279; from 5.10.210 before 5.10.221; from 5.15.149 before 5.15.162; from 6.1.79 before 6.1.95; from 6.6.18 before 6.6.35; from 6.7.6 before 6.8 — fixed in 5.10.221, 5.15.162, 5.4.279, 6.1.95, 6.6.35, 6.8

How to fix

Upgrade to a fixed version: Linux kernel 5.10.221, 5.15.162, 5.4.279, 6.1.95. Check the vendor advisory for mitigations.

References

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