From c673cbbde517b4b369a64117d0ac8290fddd9b82 Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Mon, 27 Jul 2026 07:25:17 +0000 Subject: [PATCH 1/2] netfilter: nf_tables: don't skip expired elements during walk jira VULN-34971 cve CVE-2023-52924 commit-author Florian Westphal commit 24138933b97b055d486e8064b4a1721702442a9b There is an asymmetry between commit/abort and preparation phase if the following conditions are met: 1. set is a verdict map ("1.2.3.4 : jump foo") 2. timeouts are enabled In this case, following sequence is problematic: 1. element E in set S refers to chain C 2. userspace requests removal of set S 3. kernel does a set walk to decrement chain->use count for all elements from preparation phase 4. kernel does another set walk to remove elements from the commit phase (or another walk to do a chain->use increment for all elements from abort phase) If E has already expired in 1), it will be ignored during list walk, so its use count won't have been changed. Then, when set is culled, ->destroy callback will zap the element via nf_tables_set_elem_destroy(), but this function is only safe for elements that have been deactivated earlier from the preparation phase: lack of earlier deactivate removes the element but leaks the chain use count, which results in a WARN splat when the chain gets removed later, plus a leak of the nft_chain structure. Update pipapo_get() not to skip expired elements, otherwise flush command reports bogus ENOENT errors. Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Fixes: 8d8540c4f5e0 ("netfilter: nft_set_rbtree: add timeout support") Fixes: 9d0982927e79 ("netfilter: nft_hash: add support for timeouts") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso (cherry picked from commit 24138933b97b055d486e8064b4a1721702442a9b) Signed-off-by: CIQ Kernel Automation --- net/netfilter/nf_tables_api.c | 4 ++++ net/netfilter/nft_set_hash.c | 2 -- net/netfilter/nft_set_pipapo.c | 18 ++++++++++++------ net/netfilter/nft_set_rbtree.c | 2 -- 4 files changed, 16 insertions(+), 10 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3a4a4ac28e866..1fc3df1bbc6f6 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4680,8 +4680,12 @@ static int nf_tables_dump_setelem(const struct nft_ctx *ctx, const struct nft_set_iter *iter, struct nft_set_elem *elem) { + const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); struct nft_set_dump_args *args; + if (nft_set_elem_expired(ext)) + return 0; + args = container_of(iter, struct nft_set_dump_args, iter); return nf_tables_fill_setelem(args->skb, set, elem); } diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index 70b1c8847f287..d9f08b038bb1c 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -260,8 +260,6 @@ static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set, if (iter->count < iter->skip) goto cont; - if (nft_set_elem_expired(&he->ext)) - goto cont; if (!nft_set_elem_active(&he->ext, iter->genmask)) goto cont; diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index 66a748c0d0c1a..c66626609cb9e 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -704,8 +704,7 @@ static struct nft_pipapo_elem *pipapo_get(const struct net *net, goto out; if (last) { - if (nft_set_elem_expired(&f->mt[b].e->ext) || - (genmask && + if ((genmask && !nft_set_elem_active(&f->mt[b].e->ext, genmask))) goto next_match; @@ -739,8 +738,17 @@ static struct nft_pipapo_elem *pipapo_get(const struct net *net, void *nft_pipapo_get(const struct net *net, const struct nft_set *set, const struct nft_set_elem *elem, unsigned int flags) { - return pipapo_get(net, set, (const u8 *)elem->key.val.data, - nft_genmask_cur(net)); + struct nft_pipapo_elem *ret; + + ret = pipapo_get(net, set, (const u8 *)elem->key.val.data, + nft_genmask_cur(net)); + if (IS_ERR(ret)) + return ret; + + if (nft_set_elem_expired(&ret->ext)) + return ERR_PTR(-ENOENT); + + return ret; } /** @@ -1869,8 +1877,6 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, goto cont; e = f->mt[r].e; - if (nft_set_elem_expired(&e->ext)) - goto cont; elem.priv = e; diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 82adc1975b4a1..f6b57bb92c132 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -442,8 +442,6 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx, if (iter->count < iter->skip) goto cont; - if (nft_set_elem_expired(&rbe->ext)) - goto cont; if (!nft_set_elem_active(&rbe->ext, iter->genmask)) goto cont; From 452fb9d1cf1ca710bba167e443b311b99bf0190a Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Mon, 27 Jul 2026 07:26:00 +0000 Subject: [PATCH 2/2] netfilter: nf_tables: don't fail inserts if duplicate has expired jira VULN-34725 cve CVE-2023-52925 commit-author Florian Westphal commit 7845914f45f066497ac75b30c50dbc735e84e884 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. Fixes: 24138933b97b ("netfilter: nf_tables: don't skip expired elements during walk") Signed-off-by: Florian Westphal (cherry picked from commit 7845914f45f066497ac75b30c50dbc735e84e884) Signed-off-by: CIQ Kernel Automation --- net/netfilter/nft_set_pipapo.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-) diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index c66626609cb9e..a990876bced6a 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -704,6 +704,8 @@ static struct nft_pipapo_elem *pipapo_get(const struct net *net, goto out; if (last) { + if (nft_set_elem_expired(&f->mt[b].e->ext)) + goto next_match; if ((genmask && !nft_set_elem_active(&f->mt[b].e->ext, genmask))) goto next_match; @@ -738,17 +740,8 @@ static struct nft_pipapo_elem *pipapo_get(const struct net *net, void *nft_pipapo_get(const struct net *net, const struct nft_set *set, const struct nft_set_elem *elem, unsigned int flags) { - struct nft_pipapo_elem *ret; - - ret = pipapo_get(net, set, (const u8 *)elem->key.val.data, + return pipapo_get(net, set, (const u8 *)elem->key.val.data, nft_genmask_cur(net)); - if (IS_ERR(ret)) - return ret; - - if (nft_set_elem_expired(&ret->ext)) - return ERR_PTR(-ENOENT); - - return ret; } /** @@ -1576,11 +1569,7 @@ static void nft_pipapo_activate(const struct net *net, const struct nft_set *set, const struct nft_set_elem *elem) { - struct nft_pipapo_elem *e; - - e = pipapo_get(net, set, (const u8 *)elem->key.val.data, 0); - if (IS_ERR(e)) - return; + struct nft_pipapo_elem *e = elem->priv; nft_set_elem_change_active(net, set, &e->ext); nft_set_elem_clear_busy(&e->ext); @@ -1793,10 +1782,6 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, data = (const u8 *)nft_set_ext_key(&e->ext); - e = pipapo_get(net, set, data, 0); - if (IS_ERR(e)) - return; - while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; const u8 *match_start, *match_end;