From 0741f55593547d7f25ec003b355a21d6d5fef01e Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Thu, 29 Aug 2024 17:29:32 +0200 Subject: netfilter: nf_tables: Fix percpu address space issues in nf_tables_api.c Compiling nf_tables_api.c results in several sparse warnings: nf_tables_api.c:2077:31: warning: incorrect type in return expression (different address spaces) nf_tables_api.c:2080:31: warning: incorrect type in return expression (different address spaces) nf_tables_api.c:2084:31: warning: incorrect type in return expression (different address spaces) nf_tables_api.c:2740:23: warning: incorrect type in assignment (different address spaces) nf_tables_api.c:2752:38: warning: incorrect type in assignment (different address spaces) nf_tables_api.c:2798:21: warning: incorrect type in argument 1 (different address spaces) Use {ERR_PTR,IS_ERR,PTR_ERR}_PCPU() macros when crossing between generic and percpu address spaces and add __percpu annotation to *stats pointer to fix these warnings. Found by GCC's named address space checks. There were no changes in the resulting object files. Signed-off-by: Uros Bizjak Reviewed-by: Simon Horman Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a24fe62650a7..6552ec616745 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2082,14 +2082,14 @@ static struct nft_stats __percpu *nft_stats_alloc(const struct nlattr *attr) err = nla_parse_nested_deprecated(tb, NFTA_COUNTER_MAX, attr, nft_counter_policy, NULL); if (err < 0) - return ERR_PTR(err); + return ERR_PTR_PCPU(err); if (!tb[NFTA_COUNTER_BYTES] || !tb[NFTA_COUNTER_PACKETS]) - return ERR_PTR(-EINVAL); + return ERR_PTR_PCPU(-EINVAL); newstats = netdev_alloc_pcpu_stats(struct nft_stats); if (newstats == NULL) - return ERR_PTR(-ENOMEM); + return ERR_PTR_PCPU(-ENOMEM); /* Restore old counters on this cpu, no problem. Per-cpu statistics * are not exposed to userspace. @@ -2533,10 +2533,10 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, if (nla[NFTA_CHAIN_COUNTERS]) { stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]); - if (IS_ERR(stats)) { + if (IS_ERR_PCPU(stats)) { nft_chain_release_hook(&hook); kfree(basechain); - return PTR_ERR(stats); + return PTR_ERR_PCPU(stats); } rcu_assign_pointer(basechain->stats, stats); } @@ -2650,7 +2650,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, struct nft_table *table = ctx->table; struct nft_chain *chain = ctx->chain; struct nft_chain_hook hook = {}; - struct nft_stats *stats = NULL; + struct nft_stats __percpu *stats = NULL; struct nft_hook *h, *next; struct nf_hook_ops *ops; struct nft_trans *trans; @@ -2746,8 +2746,8 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, } stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]); - if (IS_ERR(stats)) { - err = PTR_ERR(stats); + if (IS_ERR_PCPU(stats)) { + err = PTR_ERR_PCPU(stats); goto err_hooks; } } -- cgit v1.2.3 From 08e52cccae11a4148a5810f0bd5614796994d221 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 23 Jul 2024 15:08:16 +0200 Subject: netfilter: nf_tables: prefer nft_trans_elem_alloc helper Reduce references to sizeof(struct nft_trans_elem). Preparation patch to move this to a flexiable array to store elem references. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 6552ec616745..30331688301e 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6409,7 +6409,7 @@ err: nfnetlink_set_err(net, portid, NFNLGRP_NFTABLES, -ENOBUFS); } -static struct nft_trans *nft_trans_elem_alloc(struct nft_ctx *ctx, +static struct nft_trans *nft_trans_elem_alloc(const struct nft_ctx *ctx, int msg_type, struct nft_set *set) { @@ -7471,13 +7471,11 @@ static int __nft_set_catchall_flush(const struct nft_ctx *ctx, { struct nft_trans *trans; - trans = nft_trans_alloc_gfp(ctx, NFT_MSG_DELSETELEM, - sizeof(struct nft_trans_elem), GFP_KERNEL); + trans = nft_trans_elem_alloc(ctx, NFT_MSG_DELSETELEM, set); if (!trans) return -ENOMEM; nft_setelem_data_deactivate(ctx->net, set, elem_priv); - nft_trans_elem_set(trans) = set; nft_trans_elem_priv(trans) = elem_priv; nft_trans_commit_list_add_tail(ctx->net, trans); -- cgit v1.2.3 From 9adbb4198bf6cf3634032871118a7052aeaa573f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:13 +0100 Subject: netfilter: nf_tables: avoid false-positive lockdep splat on rule deletion On rule delete we get: WARNING: suspicious RCU usage net/netfilter/nf_tables_api.c:3420 RCU-list traversed in non-reader section!! 1 lock held by iptables/134: #0: ffff888008c4fcc8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid (include/linux/jiffies.h:101) nf_tables Code is fine, no other CPU can change the list because we're holding transaction mutex. Pass the needed lockdep annotation to the iterator and fix two comments for functions that are no longer restricted to rcu-only context. This is enough to resolve rule delete, but there are several other missing annotations, added in followup-patches. Fixes: 28875945ba98 ("rcu: Add support for consolidated-RCU reader checking") Reported-by: Matthieu Baerts Tested-by: Matthieu Baerts Closes: https://lore.kernel.org/netfilter-devel/da27f17f-3145-47af-ad0f-7fd2a823623e@kernel.org/ Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 30331688301e..80c285ac7e07 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3411,13 +3411,15 @@ void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr) * Rules */ -static struct nft_rule *__nft_rule_lookup(const struct nft_chain *chain, +static struct nft_rule *__nft_rule_lookup(const struct net *net, + const struct nft_chain *chain, u64 handle) { struct nft_rule *rule; // FIXME: this sucks - list_for_each_entry_rcu(rule, &chain->rules, list) { + list_for_each_entry_rcu(rule, &chain->rules, list, + lockdep_commit_lock_is_held(net)) { if (handle == rule->handle) return rule; } @@ -3425,13 +3427,14 @@ static struct nft_rule *__nft_rule_lookup(const struct nft_chain *chain, return ERR_PTR(-ENOENT); } -static struct nft_rule *nft_rule_lookup(const struct nft_chain *chain, +static struct nft_rule *nft_rule_lookup(const struct net *net, + const struct nft_chain *chain, const struct nlattr *nla) { if (nla == NULL) return ERR_PTR(-EINVAL); - return __nft_rule_lookup(chain, be64_to_cpu(nla_get_be64(nla))); + return __nft_rule_lookup(net, chain, be64_to_cpu(nla_get_be64(nla))); } static const struct nla_policy nft_rule_policy[NFTA_RULE_MAX + 1] = { @@ -3732,7 +3735,7 @@ static int nf_tables_dump_rules_done(struct netlink_callback *cb) return 0; } -/* called with rcu_read_lock held */ +/* Caller must hold rcu read lock or transaction mutex */ static struct sk_buff * nf_tables_getrule_single(u32 portid, const struct nfnl_info *info, const struct nlattr * const nla[], bool reset) @@ -3759,7 +3762,7 @@ nf_tables_getrule_single(u32 portid, const struct nfnl_info *info, return ERR_CAST(chain); } - rule = nft_rule_lookup(chain, nla[NFTA_RULE_HANDLE]); + rule = nft_rule_lookup(net, chain, nla[NFTA_RULE_HANDLE]); if (IS_ERR(rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_HANDLE]); return ERR_CAST(rule); @@ -4057,7 +4060,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, if (nla[NFTA_RULE_HANDLE]) { handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_HANDLE])); - rule = __nft_rule_lookup(chain, handle); + rule = __nft_rule_lookup(net, chain, handle); if (IS_ERR(rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_HANDLE]); return PTR_ERR(rule); @@ -4079,7 +4082,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, if (nla[NFTA_RULE_POSITION]) { pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION])); - old_rule = __nft_rule_lookup(chain, pos_handle); + old_rule = __nft_rule_lookup(net, chain, pos_handle); if (IS_ERR(old_rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_POSITION]); return PTR_ERR(old_rule); @@ -4296,7 +4299,7 @@ static int nf_tables_delrule(struct sk_buff *skb, const struct nfnl_info *info, if (chain) { if (nla[NFTA_RULE_HANDLE]) { - rule = nft_rule_lookup(chain, nla[NFTA_RULE_HANDLE]); + rule = nft_rule_lookup(info->net, chain, nla[NFTA_RULE_HANDLE]); if (IS_ERR(rule)) { if (PTR_ERR(rule) == -ENOENT && NFNL_MSG_TYPE(info->nlh->nlmsg_type) == NFT_MSG_DESTROYRULE) @@ -8101,7 +8104,7 @@ static int nf_tables_dump_obj_done(struct netlink_callback *cb) return 0; } -/* called with rcu_read_lock held */ +/* Caller must hold rcu read lock or transaction mutex */ static struct sk_buff * nf_tables_getobj_single(u32 portid, const struct nfnl_info *info, const struct nlattr * const nla[], bool reset) -- cgit v1.2.3 From 8f5f3786dba765099f12da00e6be0c26f69f2fbd Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:14 +0100 Subject: netfilter: nf_tables: avoid false-positive lockdep splats with sets Same as previous patch. All set handling functions here can be called with transaction mutex held (but not the rcu read lock). The transaction mutex prevents concurrent add/delete, so this is fine. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 80c285ac7e07..a51731d76401 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3986,7 +3986,8 @@ int nft_set_catchall_validate(const struct nft_ctx *ctx, struct nft_set *set) struct nft_set_ext *ext; int ret = 0; - list_for_each_entry_rcu(catchall, &set->catchall_list, list) { + list_for_each_entry_rcu(catchall, &set->catchall_list, list, + lockdep_commit_lock_is_held(ctx->net)) { ext = nft_set_elem_ext(set, catchall->elem); if (!nft_set_elem_active(ext, dummy_iter.genmask)) continue; @@ -4459,7 +4460,8 @@ static const struct nla_policy nft_set_desc_policy[NFTA_SET_DESC_MAX + 1] = { [NFTA_SET_DESC_CONCAT] = NLA_POLICY_NESTED_ARRAY(nft_concat_policy), }; -static struct nft_set *nft_set_lookup(const struct nft_table *table, +static struct nft_set *nft_set_lookup(const struct net *net, + const struct nft_table *table, const struct nlattr *nla, u8 genmask) { struct nft_set *set; @@ -4467,7 +4469,8 @@ static struct nft_set *nft_set_lookup(const struct nft_table *table, if (nla == NULL) return ERR_PTR(-EINVAL); - list_for_each_entry_rcu(set, &table->sets, list) { + list_for_each_entry_rcu(set, &table->sets, list, + lockdep_commit_lock_is_held(net)) { if (!nla_strcmp(nla, set->name) && nft_active_genmask(set, genmask)) return set; @@ -4517,7 +4520,7 @@ struct nft_set *nft_set_lookup_global(const struct net *net, { struct nft_set *set; - set = nft_set_lookup(table, nla_set_name, genmask); + set = nft_set_lookup(net, table, nla_set_name, genmask); if (IS_ERR(set)) { if (!nla_set_id) return set; @@ -4893,7 +4896,7 @@ static int nf_tables_getset(struct sk_buff *skb, const struct nfnl_info *info, if (!nla[NFTA_SET_TABLE]) return -EINVAL; - set = nft_set_lookup(table, nla[NFTA_SET_NAME], genmask); + set = nft_set_lookup(net, table, nla[NFTA_SET_NAME], genmask); if (IS_ERR(set)) { NL_SET_BAD_ATTR(extack, nla[NFTA_SET_NAME]); return PTR_ERR(set); @@ -5229,7 +5232,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla); - set = nft_set_lookup(table, nla[NFTA_SET_NAME], genmask); + set = nft_set_lookup(net, table, nla[NFTA_SET_NAME], genmask); if (IS_ERR(set)) { if (PTR_ERR(set) != -ENOENT) { NL_SET_BAD_ATTR(extack, nla[NFTA_SET_NAME]); @@ -5431,7 +5434,7 @@ static int nf_tables_delset(struct sk_buff *skb, const struct nfnl_info *info, set = nft_set_lookup_byhandle(table, attr, genmask); } else { attr = nla[NFTA_SET_NAME]; - set = nft_set_lookup(table, attr, genmask); + set = nft_set_lookup(net, table, attr, genmask); } if (IS_ERR(set)) { @@ -5495,7 +5498,8 @@ static int nft_set_catchall_bind_check(const struct nft_ctx *ctx, struct nft_set_ext *ext; int ret = 0; - list_for_each_entry_rcu(catchall, &set->catchall_list, list) { + list_for_each_entry_rcu(catchall, &set->catchall_list, list, + lockdep_commit_lock_is_held(ctx->net)) { ext = nft_set_elem_ext(set, catchall->elem); if (!nft_set_elem_active(ext, genmask)) continue; @@ -6261,7 +6265,7 @@ static int nft_set_dump_ctx_init(struct nft_set_dump_ctx *dump_ctx, return PTR_ERR(table); } - set = nft_set_lookup(table, nla[NFTA_SET_ELEM_LIST_SET], genmask); + set = nft_set_lookup(net, table, nla[NFTA_SET_ELEM_LIST_SET], genmask); if (IS_ERR(set)) { NL_SET_BAD_ATTR(extack, nla[NFTA_SET_ELEM_LIST_SET]); return PTR_ERR(set); @@ -7493,7 +7497,8 @@ static int nft_set_catchall_flush(const struct nft_ctx *ctx, struct nft_set_ext *ext; int ret = 0; - list_for_each_entry_rcu(catchall, &set->catchall_list, list) { + list_for_each_entry_rcu(catchall, &set->catchall_list, list, + lockdep_commit_lock_is_held(ctx->net)) { ext = nft_set_elem_ext(set, catchall->elem); if (!nft_set_elem_active(ext, genmask)) continue; @@ -7543,7 +7548,7 @@ static int nf_tables_delsetelem(struct sk_buff *skb, return PTR_ERR(table); } - set = nft_set_lookup(table, nla[NFTA_SET_ELEM_LIST_SET], genmask); + set = nft_set_lookup(net, table, nla[NFTA_SET_ELEM_LIST_SET], genmask); if (IS_ERR(set)) { NL_SET_BAD_ATTR(extack, nla[NFTA_SET_ELEM_LIST_SET]); return PTR_ERR(set); -- cgit v1.2.3 From b3e8f29d6b45e865bab9a9964709ff7413e33e85 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:15 +0100 Subject: netfilter: nf_tables: avoid false-positive lockdep splats with flowtables The transaction mutex prevents concurrent add/delete, its ok to iterate those lists outside of rcu read side critical sections. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 3 ++- net/netfilter/nf_tables_api.c | 15 +++++++++------ net/netfilter/nft_flow_offload.c | 4 ++-- 3 files changed, 13 insertions(+), 9 deletions(-) (limited to 'net/netfilter') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 91ae20cb7648..c1513bd14568 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1463,7 +1463,8 @@ struct nft_flowtable { struct nf_flowtable data; }; -struct nft_flowtable *nft_flowtable_lookup(const struct nft_table *table, +struct nft_flowtable *nft_flowtable_lookup(const struct net *net, + const struct nft_table *table, const struct nlattr *nla, u8 genmask); diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a51731d76401..9e367e134691 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8378,12 +8378,14 @@ static const struct nla_policy nft_flowtable_policy[NFTA_FLOWTABLE_MAX + 1] = { [NFTA_FLOWTABLE_FLAGS] = { .type = NLA_U32 }, }; -struct nft_flowtable *nft_flowtable_lookup(const struct nft_table *table, +struct nft_flowtable *nft_flowtable_lookup(const struct net *net, + const struct nft_table *table, const struct nlattr *nla, u8 genmask) { struct nft_flowtable *flowtable; - list_for_each_entry_rcu(flowtable, &table->flowtables, list) { + list_for_each_entry_rcu(flowtable, &table->flowtables, list, + lockdep_commit_lock_is_held(net)) { if (!nla_strcmp(nla, flowtable->name) && nft_active_genmask(flowtable, genmask)) return flowtable; @@ -8739,7 +8741,7 @@ static int nf_tables_newflowtable(struct sk_buff *skb, return PTR_ERR(table); } - flowtable = nft_flowtable_lookup(table, nla[NFTA_FLOWTABLE_NAME], + flowtable = nft_flowtable_lookup(net, table, nla[NFTA_FLOWTABLE_NAME], genmask); if (IS_ERR(flowtable)) { err = PTR_ERR(flowtable); @@ -8933,7 +8935,7 @@ static int nf_tables_delflowtable(struct sk_buff *skb, flowtable = nft_flowtable_lookup_byhandle(table, attr, genmask); } else { attr = nla[NFTA_FLOWTABLE_NAME]; - flowtable = nft_flowtable_lookup(table, attr, genmask); + flowtable = nft_flowtable_lookup(net, table, attr, genmask); } if (IS_ERR(flowtable)) { @@ -9003,7 +9005,8 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net, if (!hook_list) hook_list = &flowtable->hook_list; - list_for_each_entry_rcu(hook, hook_list, list) { + list_for_each_entry_rcu(hook, hook_list, list, + lockdep_commit_lock_is_held(net)) { if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name)) goto nla_put_failure; } @@ -9145,7 +9148,7 @@ static int nf_tables_getflowtable(struct sk_buff *skb, return PTR_ERR(table); } - flowtable = nft_flowtable_lookup(table, nla[NFTA_FLOWTABLE_NAME], + flowtable = nft_flowtable_lookup(net, table, nla[NFTA_FLOWTABLE_NAME], genmask); if (IS_ERR(flowtable)) { NL_SET_BAD_ATTR(extack, nla[NFTA_FLOWTABLE_NAME]); diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c index 2f732fae5a83..65199c23c75c 100644 --- a/net/netfilter/nft_flow_offload.c +++ b/net/netfilter/nft_flow_offload.c @@ -409,8 +409,8 @@ static int nft_flow_offload_init(const struct nft_ctx *ctx, if (!tb[NFTA_FLOW_TABLE_NAME]) return -EINVAL; - flowtable = nft_flowtable_lookup(ctx->table, tb[NFTA_FLOW_TABLE_NAME], - genmask); + flowtable = nft_flowtable_lookup(ctx->net, ctx->table, + tb[NFTA_FLOW_TABLE_NAME], genmask); if (IS_ERR(flowtable)) return PTR_ERR(flowtable); -- cgit v1.2.3 From 28b7a6b84c0aea37c5f796e14b479f1e8dbeba12 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:16 +0100 Subject: netfilter: nf_tables: avoid false-positive lockdep splats in set walker Its not possible to add or delete elements from hash and bitmap sets, as long as caller is holding the transaction mutex, so its ok to iterate the list outside of rcu read side critical section. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_set_bitmap.c | 10 ++++++---- net/netfilter/nft_set_hash.c | 3 ++- 2 files changed, 8 insertions(+), 5 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nft_set_bitmap.c b/net/netfilter/nft_set_bitmap.c index 1caa04619dc6..12390d2e994f 100644 --- a/net/netfilter/nft_set_bitmap.c +++ b/net/netfilter/nft_set_bitmap.c @@ -88,13 +88,15 @@ bool nft_bitmap_lookup(const struct net *net, const struct nft_set *set, } static struct nft_bitmap_elem * -nft_bitmap_elem_find(const struct nft_set *set, struct nft_bitmap_elem *this, +nft_bitmap_elem_find(const struct net *net, + const struct nft_set *set, struct nft_bitmap_elem *this, u8 genmask) { const struct nft_bitmap *priv = nft_set_priv(set); struct nft_bitmap_elem *be; - list_for_each_entry_rcu(be, &priv->list, head) { + list_for_each_entry_rcu(be, &priv->list, head, + lockdep_is_held(&nft_pernet(net)->commit_mutex)) { if (memcmp(nft_set_ext_key(&be->ext), nft_set_ext_key(&this->ext), set->klen) || !nft_set_elem_active(&be->ext, genmask)) @@ -132,7 +134,7 @@ static int nft_bitmap_insert(const struct net *net, const struct nft_set *set, u8 genmask = nft_genmask_next(net); u32 idx, off; - be = nft_bitmap_elem_find(set, new, genmask); + be = nft_bitmap_elem_find(net, set, new, genmask); if (be) { *elem_priv = &be->priv; return -EEXIST; @@ -201,7 +203,7 @@ nft_bitmap_deactivate(const struct net *net, const struct nft_set *set, nft_bitmap_location(set, elem->key.val.data, &idx, &off); - be = nft_bitmap_elem_find(set, this, genmask); + be = nft_bitmap_elem_find(net, set, this, genmask); if (!be) return NULL; diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index daa56dda737a..65bd291318f2 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -647,7 +647,8 @@ static void nft_hash_walk(const struct nft_ctx *ctx, struct nft_set *set, int i; for (i = 0; i < priv->buckets; i++) { - hlist_for_each_entry_rcu(he, &priv->table[i], node) { + hlist_for_each_entry_rcu(he, &priv->table[i], node, + lockdep_is_held(&nft_pernet(ctx->net)->commit_mutex)) { if (iter->count < iter->skip) goto cont; -- cgit v1.2.3 From 3567146b94afcd69d4916c880eb5b1b0e3797397 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:17 +0100 Subject: netfilter: nf_tables: avoid false-positive lockdep splats with basechain hook Like previous patches: iteration is ok if the list cannot be altered in parallel. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 9e367e134691..3b5154f2dd79 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1824,7 +1824,8 @@ nla_put_failure: return -ENOSPC; } -static int nft_dump_basechain_hook(struct sk_buff *skb, int family, +static int nft_dump_basechain_hook(struct sk_buff *skb, + const struct net *net, int family, const struct nft_base_chain *basechain, const struct list_head *hook_list) { @@ -1849,7 +1850,8 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family, if (!hook_list) hook_list = &basechain->hook_list; - list_for_each_entry_rcu(hook, hook_list, list) { + list_for_each_entry_rcu(hook, hook_list, list, + lockdep_commit_lock_is_held(net)) { if (!first) first = hook; @@ -1900,7 +1902,7 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, const struct nft_base_chain *basechain = nft_base_chain(chain); struct nft_stats __percpu *stats; - if (nft_dump_basechain_hook(skb, family, basechain, hook_list)) + if (nft_dump_basechain_hook(skb, net, family, basechain, hook_list)) goto nla_put_failure; if (nla_put_be32(skb, NFTA_CHAIN_POLICY, -- cgit v1.2.3 From ee666a541ed957937454d50afa4757924508cd74 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:18 +0100 Subject: netfilter: nf_tables: must hold rcu read lock while iterating expression type list nft shell tests trigger: WARNING: suspicious RCU usage net/netfilter/nf_tables_api.c:3125 RCU-list traversed in non-reader section!! 1 lock held by nft/2068: #0: ffff888106c6f8c8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3c/0xf0 But the transaction mutex doesn't protect this list, the nfnl subsystem mutex would, but we can't acquire it here without risk of ABBA deadlocks. Acquire the rcu read lock to avoid this issue. v3: add a comment that explains the ->inner_ops check implies expression is builtin and lack of a module owner reference is ok. Fixes: 3a07327d10a0 ("netfilter: nft_inner: support for inner tunnel header matching") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3b5154f2dd79..de8e48a5c62d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3296,25 +3296,37 @@ int nft_expr_inner_parse(const struct nft_ctx *ctx, const struct nlattr *nla, if (!tb[NFTA_EXPR_DATA] || !tb[NFTA_EXPR_NAME]) return -EINVAL; + rcu_read_lock(); + type = __nft_expr_type_get(ctx->family, tb[NFTA_EXPR_NAME]); - if (!type) - return -ENOENT; + if (!type) { + err = -ENOENT; + goto out_unlock; + } - if (!type->inner_ops) - return -EOPNOTSUPP; + if (!type->inner_ops) { + err = -EOPNOTSUPP; + goto out_unlock; + } err = nla_parse_nested_deprecated(info->tb, type->maxattr, tb[NFTA_EXPR_DATA], type->policy, NULL); if (err < 0) - goto err_nla_parse; + goto out_unlock; info->attr = nla; info->ops = type->inner_ops; + /* No module reference will be taken on type->owner. + * Presence of type->inner_ops implies that the expression + * is builtin, so it cannot go away. + */ + rcu_read_unlock(); return 0; -err_nla_parse: +out_unlock: + rcu_read_unlock(); return err; } -- cgit v1.2.3 From cddc04275f95ca3b18da5c0fb111705ac173af89 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 4 Nov 2024 10:41:19 +0100 Subject: netfilter: nf_tables: must hold rcu read lock while iterating object type list Update of stateful object triggers: WARNING: suspicious RCU usage net/netfilter/nf_tables_api.c:7759 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by nft/3060: #0: ffff88810f0578c8 (&nft_net->commit_mutex){+.+.}-{4:4}, [..] ... but this list is not protected by the transaction mutex but the nfnl nftables subsystem mutex. Switch to nft_obj_type_get which will acquire rcu read lock, bump refcount, and returns the result. v3: Dan Carpenter points out nft_obj_type_get returns error pointer, not NULL, on error. Fixes: dad3bdeef45f ("netfilter: nf_tables: fix memory leak during stateful obj update"). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index de8e48a5c62d..b7a817e483aa 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7809,9 +7809,7 @@ static int nf_tables_updobj(const struct nft_ctx *ctx, struct nft_trans *trans; int err = -ENOMEM; - if (!try_module_get(type->owner)) - return -ENOENT; - + /* caller must have obtained type->owner reference. */ trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ, sizeof(struct nft_trans_obj)); if (!trans) @@ -7879,15 +7877,16 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info, if (info->nlh->nlmsg_flags & NLM_F_REPLACE) return -EOPNOTSUPP; - type = __nft_obj_type_get(objtype, family); - if (WARN_ON_ONCE(!type)) - return -ENOENT; - if (!obj->ops->update) return 0; + type = nft_obj_type_get(net, objtype, family); + if (WARN_ON_ONCE(IS_ERR(type))) + return PTR_ERR(type); + nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla); + /* type->owner reference is put when transaction object is released. */ return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj); } -- cgit v1.2.3