CVE-2024-26910: netfilter: ipset: fix performance regression in swap operation

Severity: medium (CVSS 4.7 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: 2024-04-17 · updated 2026-06-17
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix performance regression in swap operation The patch "netfilter: ipset: fix race condition between swap/destroy and kernel side add/del/test", commit 28628fa9 fixes a race condition. But the synchronize_rcu() added to the swap function unnecessarily slows it down: it can safely be moved to destroy and use call_rcu() instead. Eric Dumazet pointed out that simply calling the destroy functions as rcu callback does not work: sets with timeout use garbage collectors which need cancelling at destroy which can wait. Therefore the destroy functions are split into two: cancelling garbage collectors safely at executing the command received by netlink and moving the remaining part only into the rcu callback.

Affected products

Linux kernel: before 5.4.269; from 5.5 before 5.10.210; from 5.11 before 5.15.149; from 5.16 before 6.1.79; from 6.2 before 6.6.18; from 6.7 before 6.7.6 — fixed in 5.10.210, 5.15.149, 5.4.269, 6.1.79, 6.6.18, 6.7.6

How to fix

Upgrade to a fixed version: Linux kernel 5.10.210, 5.15.149, 5.4.269, 6.1.79. Check the vendor advisory for mitigations.

References

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