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 be skipped. For ->deactivate(), this gets called for DELSETELEM, so it seems to me that expired elements should be skipped as well, i.e. delete request should fail with -ENOENT error.
https://git.kernel.org/stable/c/af78b0489e8898a8c9449ffc0fdd2e181916f0d4
https://git.kernel.org/stable/c/891ca5dfe3b718b441fc786014a7ba8f517da188
https://git.kernel.org/stable/c/7845914f45f066497ac75b30c50dbc735e84e884
https://git.kernel.org/stable/c/59ee68c437c562170265194a99698c805a686bb3
https://git.kernel.org/stable/c/156369a702c33ad5434a19c3a689bfb836d4e0b8