From 220ae769a529a4271e266ff238eb387ac3971e7c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Fri, 2 Jan 2026 21:46:11 +0100 Subject: [PATCH 1/3] netfilter: nft_set_pipapo: walk over current view on netlink dump MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-37652 cve CVE-2024-27017 commit-author Pablo Neira Ayuso commit 29b359cf6d95fd60730533f7f10464e95bd17c73 upstream-diff Resolved conflicts in the declarations block in nft_pipapo_walk() function. No actual diffs in the end. The generation mask can be updated while netlink dump is in progress. The pipapo set backend walk iterator cannot rely on it to infer what view of the datastructure is to be used. Add notation to specify if user wants to read/update the set. Based on patch from Florian Westphal. Fixes: 2b84e215f874 ("netfilter: nft_set_pipapo: .walk does not deal with generations") Signed-off-by: Pablo Neira Ayuso (cherry picked from commit 29b359cf6d95fd60730533f7f10464e95bd17c73) Signed-off-by: Marcin Wcisło --- include/net/netfilter/nf_tables.h | 14 ++++++++++++++ net/netfilter/nf_tables_api.c | 6 ++++++ net/netfilter/nft_set_pipapo.c | 5 +++-- 3 files changed, 23 insertions(+), 2 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index f25511d26a461..4eef6e9e8314a 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -274,9 +274,23 @@ static inline void *nft_elem_priv_cast(const struct nft_elem_priv *priv) return (void *)priv; } + +/** + * enum nft_iter_type - nftables set iterator type + * + * @NFT_ITER_READ: read-only iteration over set elements + * @NFT_ITER_UPDATE: iteration under mutex to update set element state + */ +enum nft_iter_type { + NFT_ITER_UNSPEC, + NFT_ITER_READ, + NFT_ITER_UPDATE, +}; + struct nft_set; struct nft_set_iter { u8 genmask; + enum nft_iter_type type:8; unsigned int count; unsigned int skip; int err; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index fb02ba1b0010e..c2a4050312132 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -625,6 +625,7 @@ static void nft_map_deactivate(const struct nft_ctx *ctx, struct nft_set *set) { struct nft_set_iter iter = { .genmask = nft_genmask_next(ctx->net), + .type = NFT_ITER_UPDATE, .fn = nft_mapelem_deactivate, }; @@ -5041,6 +5042,7 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set, } iter.genmask = nft_genmask_next(ctx->net); + iter.type = NFT_ITER_UPDATE; iter.skip = 0; iter.count = 0; iter.err = 0; @@ -5116,6 +5118,7 @@ static void nft_map_activate(const struct nft_ctx *ctx, struct nft_set *set) { struct nft_set_iter iter = { .genmask = nft_genmask_next(ctx->net), + .type = NFT_ITER_UPDATE, .fn = nft_mapelem_activate, }; @@ -5473,6 +5476,7 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb) args.cb = cb; args.skb = skb; args.iter.genmask = nft_genmask_cur(net); + args.iter.type = NFT_ITER_READ; args.iter.skip = cb->args[0]; args.iter.count = 0; args.iter.err = 0; @@ -6848,6 +6852,7 @@ static int nft_set_flush(struct nft_ctx *ctx, struct nft_set *set, u8 genmask) { struct nft_set_iter iter = { .genmask = genmask, + .type = NFT_ITER_UPDATE, .fn = nft_setelem_flush, }; @@ -10132,6 +10137,7 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx, continue; iter.genmask = nft_genmask_next(ctx->net); + iter.type = NFT_ITER_UPDATE; iter.skip = 0; iter.count = 0; iter.err = 0; diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index 1b9fb8d59f9d6..ebd9500ec54bd 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -2021,13 +2021,14 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, struct nft_set_iter *iter) { struct nft_pipapo *priv = nft_set_priv(set); - struct net *net = read_pnet(&set->net); struct nft_pipapo_match *m; struct nft_pipapo_field *f; int i, r; + WARN_ON_ONCE(iter->type == NFT_ITER_UNSPEC); + rcu_read_lock(); - if (iter->genmask == nft_genmask_cur(net)) + if (iter->type == NFT_ITER_READ) m = rcu_dereference(priv->match); else m = priv->clone; From f356abea6745fc303105cc7ff6eacbb081f706ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Mon, 5 Jan 2026 14:57:57 +0100 Subject: [PATCH 2/3] netfilter: nf_tables: missing iterator type in lookup walk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-37652 cve-bf CVE-2024-27017 commit-author Pablo Neira Ayuso commit efefd4f00c967d00ad7abe092554ffbb70c1a793 Add missing decorator type to lookup expression and tighten WARN_ON_ONCE check in pipapo to spot earlier that this is unset. Fixes: 29b359cf6d95 ("netfilter: nft_set_pipapo: walk over current view on netlink dump") Signed-off-by: Pablo Neira Ayuso (cherry picked from commit efefd4f00c967d00ad7abe092554ffbb70c1a793) Signed-off-by: Marcin Wcisło --- net/netfilter/nft_lookup.c | 1 + net/netfilter/nft_set_pipapo.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c index a62cb368dafff..f16ebe94e98a8 100644 --- a/net/netfilter/nft_lookup.c +++ b/net/netfilter/nft_lookup.c @@ -217,6 +217,7 @@ static int nft_lookup_validate(const struct nft_ctx *ctx, return 0; iter.genmask = nft_genmask_next(ctx->net); + iter.type = NFT_ITER_UPDATE; iter.skip = 0; iter.count = 0; iter.err = 0; diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index ebd9500ec54bd..73523310f0b83 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -2025,7 +2025,8 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, struct nft_pipapo_field *f; int i, r; - WARN_ON_ONCE(iter->type == NFT_ITER_UNSPEC); + WARN_ON_ONCE(iter->type != NFT_ITER_READ && + iter->type != NFT_ITER_UPDATE); rcu_read_lock(); if (iter->type == NFT_ITER_READ) From 885832033b5a048cb280fed758b3379d09a0cdc5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Sun, 4 Jan 2026 22:40:01 +0100 Subject: [PATCH 3/3] netfilter: nf_tables: restore set elements when delete set fails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-37622 cve CVE-2024-27012 commit-author Pablo Neira Ayuso commit e79b47a8615d42c68aaeb68971593333667382ed upstream-diff Accounted for the missing commit 0e1ea651c9717ddcd8e0648d8468477a31867b0a. From abort path, nft_mapelem_activate() needs to restore refcounters to the original state. Currently, it uses the set->ops->walk() to iterate over these set elements. The existing set iterator skips inactive elements in the next generation, this does not work from the abort path to restore the original state since it has to skip active elements instead (not inactive ones). This patch moves the check for inactive elements to the set iterator callback, then it reverses the logic for the .activate case which needs to skip active elements. Toggle next generation bit for elements when delete set command is invoked and call nft_clear() from .activate (abort) path to restore the next generation bit. The splat below shows an object in mappings memleak: [43929.457523] ------------[ cut here ]------------ [43929.457532] WARNING: CPU: 0 PID: 1139 at include/net/netfilter/nf_tables.h:1237 nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables] [...] [43929.458014] RIP: 0010:nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables] [43929.458076] Code: 83 f8 01 77 ab 49 8d 7c 24 08 e8 37 5e d0 de 49 8b 6c 24 08 48 8d 7d 50 e8 e9 5c d0 de 8b 45 50 8d 50 ff 89 55 50 85 c0 75 86 <0f> 0b eb 82 0f 0b eb b3 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 [43929.458081] RSP: 0018:ffff888140f9f4b0 EFLAGS: 00010246 [43929.458086] RAX: 0000000000000000 RBX: ffff8881434f5288 RCX: dffffc0000000000 [43929.458090] RDX: 00000000ffffffff RSI: ffffffffa26d28a7 RDI: ffff88810ecc9550 [43929.458093] RBP: ffff88810ecc9500 R08: 0000000000000001 R09: ffffed10281f3e8f [43929.458096] R10: 0000000000000003 R11: ffff0000ffff0000 R12: ffff8881434f52a0 [43929.458100] R13: ffff888140f9f5f4 R14: ffff888151c7a800 R15: 0000000000000002 [43929.458103] FS: 00007f0c687c4740(0000) GS:ffff888390800000(0000) knlGS:0000000000000000 [43929.458107] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [43929.458111] CR2: 00007f58dbe5b008 CR3: 0000000123602005 CR4: 00000000001706f0 [43929.458114] Call Trace: [43929.458118] [43929.458121] ? __warn+0x9f/0x1a0 [43929.458127] ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables] [43929.458188] ? report_bug+0x1b1/0x1e0 [43929.458196] ? handle_bug+0x3c/0x70 [43929.458200] ? exc_invalid_op+0x17/0x40 [43929.458211] ? nft_setelem_data_deactivate+0xd7/0xf0 [nf_tables] [43929.458271] ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables] [43929.458332] nft_mapelem_deactivate+0x24/0x30 [nf_tables] [43929.458392] nft_rhash_walk+0xdd/0x180 [nf_tables] [43929.458453] ? __pfx_nft_rhash_walk+0x10/0x10 [nf_tables] [43929.458512] ? rb_insert_color+0x2e/0x280 [43929.458520] nft_map_deactivate+0xdc/0x1e0 [nf_tables] [43929.458582] ? __pfx_nft_map_deactivate+0x10/0x10 [nf_tables] [43929.458642] ? __pfx_nft_mapelem_deactivate+0x10/0x10 [nf_tables] [43929.458701] ? __rcu_read_unlock+0x46/0x70 [43929.458709] nft_delset+0xff/0x110 [nf_tables] [43929.458769] nft_flush_table+0x16f/0x460 [nf_tables] [43929.458830] nf_tables_deltable+0x501/0x580 [nf_tables] Fixes: 628bd3e49cba ("netfilter: nf_tables: drop map element references from preparation phase") Signed-off-by: Pablo Neira Ayuso (cherry picked from commit e79b47a8615d42c68aaeb68971593333667382ed) Signed-off-by: Marcin Wcisło --- net/netfilter/nf_tables_api.c | 43 ++++++++++++++++++++++++++++++---- net/netfilter/nft_set_bitmap.c | 4 +--- net/netfilter/nft_set_hash.c | 8 ++----- net/netfilter/nft_set_pipapo.c | 5 +--- net/netfilter/nft_set_rbtree.c | 4 +--- 5 files changed, 44 insertions(+), 20 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index c2a4050312132..f4a0ec26be956 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -591,6 +591,12 @@ static int nft_mapelem_deactivate(const struct nft_ctx *ctx, const struct nft_set_iter *iter, struct nft_set_elem *elem) { + struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); + + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + + nft_set_elem_change_active(ctx->net, set, ext); nft_setelem_data_deactivate(ctx->net, set, elem); return 0; @@ -615,6 +621,7 @@ static void nft_map_catchall_deactivate(const struct nft_ctx *ctx, if (!nft_set_elem_active(ext, genmask)) continue; + nft_set_elem_change_active(ctx->net, set, ext); elem.priv = catchall->elem; nft_setelem_data_deactivate(ctx->net, set, &elem); break; @@ -3484,6 +3491,9 @@ int nft_setelem_validate(const struct nft_ctx *ctx, struct nft_set *set, const struct nft_data *data; int err; + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) && *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END) return 0; @@ -3507,7 +3517,9 @@ int nft_setelem_validate(const struct nft_ctx *ctx, struct nft_set *set, int nft_set_catchall_validate(const struct nft_ctx *ctx, struct nft_set *set) { - u8 genmask = nft_genmask_next(ctx->net); + struct nft_set_iter dummy_iter = { + .genmask = nft_genmask_next(ctx->net), + }; struct nft_set_elem_catchall *catchall; struct nft_set_elem elem; struct nft_set_ext *ext; @@ -3515,11 +3527,11 @@ int nft_set_catchall_validate(const struct nft_ctx *ctx, struct nft_set *set) list_for_each_entry_rcu(catchall, &set->catchall_list, list) { ext = nft_set_elem_ext(set, catchall->elem); - if (!nft_set_elem_active(ext, genmask)) + if (!nft_set_elem_active(ext, dummy_iter.genmask)) continue; elem.priv = catchall->elem; - ret = nft_setelem_validate(ctx, set, NULL, &elem); + ret = nft_setelem_validate(ctx, set, &dummy_iter, &elem); if (ret < 0) return ret; } @@ -4996,6 +5008,11 @@ static int nf_tables_bind_check_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); + + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + return nft_setelem_data_validate(ctx, set, elem); } @@ -5090,6 +5107,13 @@ static int nft_mapelem_activate(const struct nft_ctx *ctx, const struct nft_set_iter *iter, struct nft_set_elem *elem) { + struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); + + /* called from abort path, reverse check to undo changes. */ + if (nft_set_elem_active(ext, iter->genmask)) + return 0; + + nft_clear(ctx->net, ext); nft_setelem_data_activate(ctx->net, set, elem); return 0; @@ -5108,6 +5132,7 @@ static void nft_map_catchall_activate(const struct nft_ctx *ctx, if (!nft_set_elem_active(ext, genmask)) continue; + nft_clear(ctx->net, ext); elem.priv = catchall->elem; nft_setelem_data_activate(ctx->net, set, &elem); break; @@ -5380,6 +5405,9 @@ static int nf_tables_dump_setelem(const struct nft_ctx *ctx, const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); struct nft_set_dump_args *args; + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + if (nft_set_elem_expired(ext) || nft_set_elem_is_dead(ext)) return 0; @@ -6113,7 +6141,7 @@ static void nft_setelem_activate(struct net *net, struct nft_set *set, struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); if (nft_setelem_is_catchall(set, elem)) { - nft_set_elem_change_active(net, set, ext); + nft_clear(net, ext); } else { set->ops->activate(net, set, elem); } @@ -6787,8 +6815,12 @@ static int nft_setelem_flush(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_trans *trans; + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + trans = nft_trans_alloc_gfp(ctx, NFT_MSG_DELSETELEM, sizeof(struct nft_trans_elem), GFP_ATOMIC); if (!trans) @@ -10056,6 +10088,9 @@ static int nf_tables_loop_check_setelem(const struct nft_ctx *ctx, { const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); + if (!nft_set_elem_active(ext, iter->genmask)) + return 0; + if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) && *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END) return 0; diff --git a/net/netfilter/nft_set_bitmap.c b/net/netfilter/nft_set_bitmap.c index 30213bcfce648..605b544468859 100644 --- a/net/netfilter/nft_set_bitmap.c +++ b/net/netfilter/nft_set_bitmap.c @@ -173,7 +173,7 @@ static void nft_bitmap_activate(const struct net *net, nft_bitmap_location(set, nft_set_ext_key(&be->ext), &idx, &off); /* Enter 11 state. */ priv->bitmap[idx] |= (genmask << off); - nft_set_elem_change_active(net, set, &be->ext); + nft_clear(net, &be->ext); } static void nft_bitmap_flush(const struct net *net, @@ -224,8 +224,6 @@ static void nft_bitmap_walk(const struct nft_ctx *ctx, list_for_each_entry_rcu(be, &priv->list, head) { if (iter->count < iter->skip) goto cont; - if (!nft_set_elem_active(&be->ext, iter->genmask)) - goto cont; elem.priv = &be->priv; diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index 191164d0a3431..582d4c1053660 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -196,7 +196,7 @@ static void nft_rhash_activate(const struct net *net, const struct nft_set *set, { struct nft_rhash_elem *he = nft_elem_priv_cast(elem->priv); - nft_set_elem_change_active(net, set, &he->ext); + nft_clear(net, &he->ext); } static void nft_rhash_flush(const struct net *net, @@ -283,8 +283,6 @@ 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_active(&he->ext, iter->genmask)) - goto cont; elem.priv = &he->priv; @@ -612,7 +610,7 @@ static void nft_hash_activate(const struct net *net, const struct nft_set *set, { struct nft_hash_elem *he = nft_elem_priv_cast(elem->priv); - nft_set_elem_change_active(net, set, &he->ext); + nft_clear(net, &he->ext); } static void nft_hash_flush(const struct net *net, @@ -666,8 +664,6 @@ static void nft_hash_walk(const struct nft_ctx *ctx, struct nft_set *set, hlist_for_each_entry_rcu(he, &priv->table[i], node) { if (iter->count < iter->skip) goto cont; - if (!nft_set_elem_active(&he->ext, iter->genmask)) - goto cont; elem.priv = &he->priv; diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index 73523310f0b83..fdcb7b0ff0468 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -1754,7 +1754,7 @@ static void nft_pipapo_activate(const struct net *net, { struct nft_pipapo_elem *e = nft_elem_priv_cast(elem->priv); - nft_set_elem_change_active(net, set, &e->ext); + nft_clear(net, &e->ext); } /** @@ -2052,9 +2052,6 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, e = f->mt[r].e; - if (!nft_set_elem_active(&e->ext, iter->genmask)) - goto cont; - elem.priv = &e->priv; iter->err = iter->fn(ctx, set, iter, &elem); diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 7567a96b3304a..64f77bc7e80ed 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -530,7 +530,7 @@ static void nft_rbtree_activate(const struct net *net, { struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem->priv); - nft_set_elem_change_active(net, set, &rbe->ext); + nft_clear(net, &rbe->ext); } static void nft_rbtree_flush(const struct net *net, @@ -596,8 +596,6 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx, if (iter->count < iter->skip) goto cont; - if (!nft_set_elem_active(&rbe->ext, iter->genmask)) - goto cont; elem.priv = &rbe->priv;