From ddbd8be68941985f166f5107109a90ce13147c44 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 20 Jul 2023 00:29:58 +0200 Subject: netfilter: nf_tables: fix spurious set element insertion failure On some platforms there is a padding hole in the nft_verdict structure, between the verdict code and the chain pointer. On element insertion, if the new element clashes with an existing one and NLM_F_EXCL flag isn't set, we want to ignore the -EEXIST error as long as the data associated with duplicated element is the same as the existing one. The data equality check uses memcmp. For normal data (NFT_DATA_VALUE) this works fine, but for NFT_DATA_VERDICT padding area leads to spurious failure even if the verdict data is the same. This then makes the insertion fail with 'already exists' error, even though the new "key : data" matches an existing entry and userspace told the kernel that it doesn't want to receive an error indication. Fixes: c016c7e45ddf ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion") Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 237f739da3ca..79c7eee33dcd 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -10517,6 +10517,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, if (!tb[NFTA_VERDICT_CODE]) return -EINVAL; + + /* zero padding hole for memcmp */ + memset(data, 0, sizeof(*data)); data->verdict.code = ntohl(nla_get_be32(tb[NFTA_VERDICT_CODE])); switch (data->verdict.code) { -- cgit v1.2.3-58-ga151 From 314c82841602a111c04a7210c21dc77e0d560242 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 18 Jul 2023 01:30:33 +0200 Subject: netfilter: nf_tables: can't schedule in nft_chain_validate Can be called via nft set element list iteration, which may acquire rcu and/or bh read lock (depends on set type). BUG: sleeping function called from invalid context at net/netfilter/nf_tables_api.c:3353 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1232, name: nft preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 2 locks held by nft/1232: #0: ffff8881180e3ea8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid #1: ffffffff83f5f540 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire Call Trace: nft_chain_validate nft_lookup_validate_setelem nft_pipapo_walk nft_lookup_validate nft_chain_validate nft_immediate_validate nft_chain_validate nf_tables_validate nf_tables_abort No choice but to move it to nf_tables_validate(). Fixes: 81ea01066741 ("netfilter: nf_tables: add rescheduling points during loop detection walks") Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 79c7eee33dcd..41e7d21d4429 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3685,8 +3685,6 @@ int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain) if (err < 0) return err; } - - cond_resched(); } return 0; @@ -3710,6 +3708,8 @@ static int nft_table_validate(struct net *net, const struct nft_table *table) err = nft_chain_validate(&ctx, chain); if (err < 0) return err; + + cond_resched(); } return 0; -- cgit v1.2.3-58-ga151 From 87b5a5c209405cb6b57424cdfa226a6dbd349232 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 19 Jul 2023 21:08:21 +0200 Subject: netfilter: nft_set_pipapo: fix improper element removal end key should be equal to start unless NFT_SET_EXT_KEY_END is present. Its possible to add elements that only have a start key ("{ 1.0.0.0 . 2.0.0.0 }") without an internval end. Insertion treats this via: if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) end = (const u8 *)nft_set_ext_key_end(ext)->data; else end = start; but removal side always uses nft_set_ext_key_end(). This is wrong and leads to garbage remaining in the set after removal next lookup/insert attempt will give: BUG: KASAN: slab-use-after-free in pipapo_get+0x8eb/0xb90 Read of size 1 at addr ffff888100d50586 by task nft-pipapo_uaf_/1399 Call Trace: kasan_report+0x105/0x140 pipapo_get+0x8eb/0xb90 nft_pipapo_insert+0x1dc/0x1710 nf_tables_newsetelem+0x31f5/0x4e00 .. Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Reported-by: lonial con Reviewed-by: Stefano Brivio Signed-off-by: Florian Westphal --- net/netfilter/nft_set_pipapo.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index db526cb7a485..49915a2a58eb 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -1929,7 +1929,11 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, int i, start, rules_fx; match_start = data; - match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; + + if (nft_set_ext_exists(&e->ext, NFT_SET_EXT_KEY_END)) + match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; + else + match_end = data; start = first_rule; rules_fx = rules_f0; -- cgit v1.2.3-58-ga151 From 751d460ccff3137212f47d876221534bf0490996 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 19 Jul 2023 20:19:43 +0200 Subject: netfilter: nf_tables: skip bound chain in netns release path Skip bound chain from netns release path, the rule that owns this chain releases these objects. Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 41e7d21d4429..40bff6e2ea5d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -10802,6 +10802,9 @@ static void __nft_release_table(struct net *net, struct nft_table *table) ctx.family = table->family; ctx.table = table; list_for_each_entry(chain, &table->chains, list) { + if (nft_chain_is_bound(chain)) + continue; + ctx.chain = chain; list_for_each_entry_safe(rule, nr, &chain->rules, list) { list_del(&rule->list); -- cgit v1.2.3-58-ga151 From 6eaf41e87a223ae6f8e7a28d6e78384ad7e407f8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 20 Jul 2023 09:17:21 +0200 Subject: netfilter: nf_tables: skip bound chain on rule flush Skip bound chain when flushing table rules, the rule that owns this chain releases these objects. Otherwise, the following warning is triggered: WARNING: CPU: 2 PID: 1217 at net/netfilter/nf_tables_api.c:2013 nf_tables_chain_destroy+0x1f7/0x210 [nf_tables] CPU: 2 PID: 1217 Comm: chain-flush Not tainted 6.1.39 #1 RIP: 0010:nf_tables_chain_destroy+0x1f7/0x210 [nf_tables] Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING") Reported-by: Kevin Rich Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 40bff6e2ea5d..b9a4d3fd1d34 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4087,6 +4087,8 @@ static int nf_tables_delrule(struct sk_buff *skb, const struct nfnl_info *info, list_for_each_entry(chain, &table->chains, list) { if (!nft_is_active_next(net, chain)) continue; + if (nft_chain_is_bound(chain)) + continue; ctx.chain = chain; err = nft_delrule_by_chain(&ctx); -- cgit v1.2.3-58-ga151