CVE-2023-53304: netfilter: nft_set_rbtree: fix overlap expiration walk

Severity: medium (CVSS 5.5 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: 2025-09-16 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_rbtree: fix overlap expiration walk The lazy gc on insert that should remove timed-out entries fails to release the other half of the interval, if any. Can be reproduced with tests/shell/testcases/sets/0044interval_overlap_0 in nftables.git and kmemleak enabled kernel. Second bug is the use of rbe_prev vs. prev pointer. If rbe_prev() returns NULL after at least one iteration, rbe_prev points to element that is not an end interval, hence it should not be removed. Lastly, check the genmask of the end interval if this is active in the current generation.

Affected products

Linux kernel: from 5.10.166 before 5.10.190; from 5.15.91 before 5.15.124; from 6.1.9 before 6.1.43; from 6.2.1 before 6.4.8; 6.2, 6.2-rc6, 6.2-rc7, 6.2-rc8, 6.5-rc1, 6.5-rc2 (+1) — fixed in 5.10.190, 5.15.124, 6.1.43, 6.4.8

How to fix

Upgrade to a fixed version: Linux kernel 5.10.190, 5.15.124, 6.1.43, 6.4.8. Check the vendor advisory for mitigations.

References

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