CVE-2023-52925

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: don't fail inserts if duplicate has expired

nftables selftests fail:

run-tests.sh testcases/sets/0044interval_overlap_0

Expected: 0-2 . 0-3, got:

W: [FAILED] ./testcases/sets/0044interval_overlap_0: got 1

Insertion must ignore duplicate but expired entries.

Moreover, there is a strange asymmetry in nft_pipapo_activate:

It refetches the current element, whereas the other ->activate callbacks

(bitmap, hash, rhash, rbtree) use elem->priv.

Same for .remove: other set implementations take elem->priv,

nft_pipapo_remove fetches elem->priv, then does a relookup,

remove this.

I suspect this was the reason for the change that prompted the

removal of the expired check in pipapo_get() in the first place,

but skipping exired elements there makes no sense to me, this helper

is used for normal get requests, insertions (duplicate check)

and deactivate callback.

In first two cases expired elements must

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References