--- /dev/null
+From stable-owner@vger.kernel.org Sun Aug 13 00:09:15 2023
+From: Pablo Neira Ayuso <pablo@netfilter.org>
+Date: Sun, 13 Aug 2023 00:09:03 +0200
+Subject: netfilter: nf_tables: report use refcount overflow
+To: netfilter-devel@vger.kernel.org
+Cc: gregkh@linuxfoundation.org, stable@vger.kernel.org, sashal@kernel.org
+Message-ID: <20230812220903.56667-3-pablo@netfilter.org>
+
+From: Pablo Neira Ayuso <pablo@netfilter.org>
+
+commit 1689f25924ada8fe14a4a82c38925d04994c7142 upstream.
+
+Overflow use refcount checks are not complete.
+
+Add helper function to deal with object reference counter tracking.
+Report -EMFILE in case UINT_MAX is reached.
+
+nft_use_dec() splats in case that reference counter underflows,
+which should not ever happen.
+
+Add nft_use_inc_restore() and nft_use_dec_restore() which are used
+to restore reference counter from error and abort paths.
+
+Use u32 in nft_flowtable and nft_object since helper functions cannot
+work on bitfields.
+
+Remove the few early incomplete checks now that the helper functions
+are in place and used to check for refcount overflow.
+
+Fixes: 96518518cc41 ("netfilter: add nftables")
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/net/netfilter/nf_tables.h | 31 ++++++-
+ net/netfilter/nf_tables_api.c | 166 +++++++++++++++++++++++---------------
+ net/netfilter/nft_flow_offload.c | 6 -
+ net/netfilter/nft_objref.c | 8 +
+ 4 files changed, 140 insertions(+), 71 deletions(-)
+
+--- a/include/net/netfilter/nf_tables.h
++++ b/include/net/netfilter/nf_tables.h
+@@ -992,6 +992,29 @@ int __nft_release_basechain(struct nft_c
+
+ unsigned int nft_do_chain(struct nft_pktinfo *pkt, void *priv);
+
++static inline bool nft_use_inc(u32 *use)
++{
++ if (*use == UINT_MAX)
++ return false;
++
++ (*use)++;
++
++ return true;
++}
++
++static inline void nft_use_dec(u32 *use)
++{
++ WARN_ON_ONCE((*use)-- == 0);
++}
++
++/* For error and abort path: restore use counter to previous state. */
++static inline void nft_use_inc_restore(u32 *use)
++{
++ WARN_ON_ONCE(!nft_use_inc(use));
++}
++
++#define nft_use_dec_restore nft_use_dec
++
+ /**
+ * struct nft_table - nf_tables table
+ *
+@@ -1050,8 +1073,8 @@ struct nft_object {
+ struct list_head list;
+ char *name;
+ struct nft_table *table;
+- u32 genmask:2,
+- use:30;
++ u32 genmask:2;
++ u32 use;
+ u64 handle;
+ /* runtime data below here */
+ const struct nft_object_ops *ops ____cacheline_aligned;
+@@ -1149,8 +1172,8 @@ struct nft_flowtable {
+ int hooknum;
+ int priority;
+ int ops_len;
+- u32 genmask:2,
+- use:30;
++ u32 genmask:2;
++ u32 use;
+ u64 handle;
+ /* runtime data below here */
+ struct nf_hook_ops *ops ____cacheline_aligned;
+--- a/net/netfilter/nf_tables_api.c
++++ b/net/netfilter/nf_tables_api.c
+@@ -266,7 +266,7 @@ static int nft_delchain(struct nft_ctx *
+ if (err < 0)
+ return err;
+
+- ctx->table->use--;
++ nft_use_dec(&ctx->table->use);
+ nft_deactivate_next(ctx->net, ctx->chain);
+
+ return err;
+@@ -307,7 +307,7 @@ nf_tables_delrule_deactivate(struct nft_
+ /* You cannot delete the same rule twice */
+ if (nft_is_active_next(ctx->net, rule)) {
+ nft_deactivate_next(ctx->net, rule);
+- ctx->chain->use--;
++ nft_use_dec(&ctx->chain->use);
+ return 0;
+ }
+ return -ENOENT;
+@@ -396,7 +396,7 @@ static int nft_delset(const struct nft_c
+ return err;
+
+ nft_deactivate_next(ctx->net, set);
+- ctx->table->use--;
++ nft_use_dec(&ctx->table->use);
+
+ return err;
+ }
+@@ -428,7 +428,7 @@ static int nft_delobj(struct nft_ctx *ct
+ return err;
+
+ nft_deactivate_next(ctx->net, obj);
+- ctx->table->use--;
++ nft_use_dec(&ctx->table->use);
+
+ return err;
+ }
+@@ -462,7 +462,7 @@ static int nft_delflowtable(struct nft_c
+ return err;
+
+ nft_deactivate_next(ctx->net, flowtable);
+- ctx->table->use--;
++ nft_use_dec(&ctx->table->use);
+
+ return err;
+ }
+@@ -1660,9 +1660,6 @@ static int nf_tables_addchain(struct nft
+ struct nft_rule **rules;
+ int err;
+
+- if (table->use == UINT_MAX)
+- return -EOVERFLOW;
+-
+ if (nla[NFTA_CHAIN_HOOK]) {
+ struct nft_chain_hook hook;
+ struct nf_hook_ops *ops;
+@@ -1734,6 +1731,11 @@ static int nf_tables_addchain(struct nft
+ if (err < 0)
+ goto err1;
+
++ if (!nft_use_inc(&table->use)) {
++ err = -EMFILE;
++ goto err_use;
++ }
++
+ err = rhltable_insert_key(&table->chains_ht, chain->name,
+ &chain->rhlhead, nft_chain_ht_params);
+ if (err)
+@@ -1746,11 +1748,12 @@ static int nf_tables_addchain(struct nft
+ goto err2;
+ }
+
+- table->use++;
+ list_add_tail_rcu(&chain->list, &table->chains);
+
+ return 0;
+ err2:
++ nft_use_dec_restore(&table->use);
++err_use:
+ nf_tables_unregister_hook(net, table, chain);
+ err1:
+ nf_tables_chain_destroy(ctx);
+@@ -2692,9 +2695,6 @@ static int nf_tables_newrule(struct net
+ return -EINVAL;
+ handle = nf_tables_alloc_handle(table);
+
+- if (chain->use == UINT_MAX)
+- return -EOVERFLOW;
+-
+ 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);
+@@ -2770,23 +2770,28 @@ static int nf_tables_newrule(struct net
+ expr = nft_expr_next(expr);
+ }
+
++ if (!nft_use_inc(&chain->use)) {
++ err = -EMFILE;
++ goto err2;
++ }
++
+ if (nlh->nlmsg_flags & NLM_F_REPLACE) {
+ trans = nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule);
+ if (trans == NULL) {
+ err = -ENOMEM;
+- goto err2;
++ goto err_destroy_flow_rule;
+ }
+ err = nft_delrule(&ctx, old_rule);
+ if (err < 0) {
+ nft_trans_destroy(trans);
+- goto err2;
++ goto err_destroy_flow_rule;
+ }
+
+ list_add_tail_rcu(&rule->list, &old_rule->list);
+ } else {
+ if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) {
+ err = -ENOMEM;
+- goto err2;
++ goto err_destroy_flow_rule;
+ }
+
+ if (nlh->nlmsg_flags & NLM_F_APPEND) {
+@@ -2802,12 +2807,14 @@ static int nf_tables_newrule(struct net
+ }
+ }
+ kvfree(info);
+- chain->use++;
+
+ if (nft_net->validate_state == NFT_VALIDATE_DO)
+ return nft_table_validate(net, table);
+
+ return 0;
++
++err_destroy_flow_rule:
++ nft_use_dec_restore(&chain->use);
+ err2:
+ nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE_ERROR);
+ nf_tables_rule_destroy(&ctx, rule);
+@@ -3625,10 +3632,15 @@ static int nf_tables_newset(struct net *
+ if (ops->privsize != NULL)
+ size = ops->privsize(nla, &desc);
+
++ if (!nft_use_inc(&table->use)) {
++ err = -EMFILE;
++ goto err1;
++ }
++
+ set = kvzalloc(sizeof(*set) + size + udlen, GFP_KERNEL);
+ if (!set) {
+ err = -ENOMEM;
+- goto err1;
++ goto err_alloc;
+ }
+
+ name = nla_strdup(nla[NFTA_SET_NAME], GFP_KERNEL);
+@@ -3675,7 +3687,7 @@ static int nf_tables_newset(struct net *
+ goto err4;
+
+ list_add_tail_rcu(&set->list, &table->sets);
+- table->use++;
++
+ return 0;
+
+ err4:
+@@ -3684,6 +3696,8 @@ err3:
+ kfree(set->name);
+ err2:
+ kvfree(set);
++err_alloc:
++ nft_use_dec_restore(&table->use);
+ err1:
+ module_put(to_set_type(ops)->owner);
+ return err;
+@@ -3770,9 +3784,6 @@ int nf_tables_bind_set(const struct nft_
+ struct nft_set_binding *i;
+ struct nft_set_iter iter;
+
+- if (set->use == UINT_MAX)
+- return -EOVERFLOW;
+-
+ if (!list_empty(&set->bindings) && nft_set_is_anonymous(set))
+ return -EBUSY;
+
+@@ -3797,10 +3808,12 @@ int nf_tables_bind_set(const struct nft_
+ return iter.err;
+ }
+ bind:
++ if (!nft_use_inc(&set->use))
++ return -EMFILE;
++
+ binding->chain = ctx->chain;
+ list_add_tail_rcu(&binding->list, &set->bindings);
+ nft_set_trans_bind(ctx, set);
+- set->use++;
+
+ return 0;
+ }
+@@ -3825,7 +3838,7 @@ void nf_tables_activate_set(const struct
+ if (nft_set_is_anonymous(set))
+ nft_clear(ctx->net, set);
+
+- set->use++;
++ nft_use_inc_restore(&set->use);
+ }
+ EXPORT_SYMBOL_GPL(nf_tables_activate_set);
+
+@@ -3841,17 +3854,17 @@ void nf_tables_deactivate_set(const stru
+ else
+ list_del_rcu(&binding->list);
+
+- set->use--;
++ nft_use_dec(&set->use);
+ break;
+ case NFT_TRANS_PREPARE:
+ if (nft_set_is_anonymous(set))
+ nft_deactivate_next(ctx->net, set);
+
+- set->use--;
++ nft_use_dec(&set->use);
+ return;
+ case NFT_TRANS_ABORT:
+ case NFT_TRANS_RELEASE:
+- set->use--;
++ nft_use_dec(&set->use);
+ /* fall through */
+ default:
+ nf_tables_unbind_set(ctx, set, binding,
+@@ -4433,7 +4446,7 @@ void nft_set_elem_destroy(const struct n
+ }
+ }
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF))
+- (*nft_set_ext_obj(ext))->use--;
++ nft_use_dec(&(*nft_set_ext_obj(ext))->use);
+ kfree(elem);
+ }
+ EXPORT_SYMBOL_GPL(nft_set_elem_destroy);
+@@ -4542,8 +4555,16 @@ static int nft_add_set_elem(struct nft_c
+ set->objtype, genmask);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
++ obj = NULL;
++ goto err2;
++ }
++
++ if (!nft_use_inc(&obj->use)) {
++ err = -EMFILE;
++ obj = NULL;
+ goto err2;
+ }
++
+ nft_set_ext_add(&tmpl, NFT_SET_EXT_OBJREF);
+ }
+
+@@ -4608,10 +4629,8 @@ static int nft_add_set_elem(struct nft_c
+ udata->len = ulen - 1;
+ nla_memcpy(&udata->data, nla[NFTA_SET_ELEM_USERDATA], ulen);
+ }
+- if (obj) {
++ if (obj)
+ *nft_set_ext_obj(ext) = obj;
+- obj->use++;
+- }
+
+ trans = nft_trans_elem_alloc(ctx, NFT_MSG_NEWSETELEM, set);
+ if (trans == NULL)
+@@ -4657,13 +4676,14 @@ err6:
+ err5:
+ kfree(trans);
+ err4:
+- if (obj)
+- obj->use--;
+ kfree(elem.priv);
+ err3:
+ if (nla[NFTA_SET_ELEM_DATA] != NULL)
+ nft_data_release(&elem.data.val, desc.type);
+ err2:
++ if (obj)
++ nft_use_dec_restore(&obj->use);
++
+ nft_data_release(&elem.key.val, NFT_DATA_VALUE);
+ err1:
+ return err;
+@@ -4723,11 +4743,14 @@ static int nf_tables_newsetelem(struct n
+ */
+ void nft_data_hold(const struct nft_data *data, enum nft_data_types type)
+ {
++ struct nft_chain *chain;
++
+ if (type == NFT_DATA_VERDICT) {
+ switch (data->verdict.code) {
+ case NFT_JUMP:
+ case NFT_GOTO:
+- data->verdict.chain->use++;
++ chain = data->verdict.chain;
++ nft_use_inc_restore(&chain->use);
+ break;
+ }
+ }
+@@ -4742,7 +4765,7 @@ static void nft_set_elem_activate(const
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA))
+ nft_data_hold(nft_set_ext_data(ext), set->dtype);
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF))
+- (*nft_set_ext_obj(ext))->use++;
++ nft_use_inc_restore(&(*nft_set_ext_obj(ext))->use);
+ }
+
+ static void nft_set_elem_deactivate(const struct net *net,
+@@ -4754,7 +4777,7 @@ static void nft_set_elem_deactivate(cons
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA))
+ nft_data_release(nft_set_ext_data(ext), set->dtype);
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF))
+- (*nft_set_ext_obj(ext))->use--;
++ nft_use_dec(&(*nft_set_ext_obj(ext))->use);
+ }
+
+ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
+@@ -5151,9 +5174,14 @@ static int nf_tables_newobj(struct net *
+
+ nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla);
+
++ if (!nft_use_inc(&table->use))
++ return -EMFILE;
++
+ type = nft_obj_type_get(net, objtype);
+- if (IS_ERR(type))
+- return PTR_ERR(type);
++ if (IS_ERR(type)) {
++ err = PTR_ERR(type);
++ goto err_type;
++ }
+
+ obj = nft_obj_init(&ctx, type, nla[NFTA_OBJ_DATA]);
+ if (IS_ERR(obj)) {
+@@ -5174,7 +5202,7 @@ static int nf_tables_newobj(struct net *
+ goto err3;
+
+ list_add_tail_rcu(&obj->list, &table->objects);
+- table->use++;
++
+ return 0;
+ err3:
+ kfree(obj->name);
+@@ -5184,6 +5212,9 @@ err2:
+ kfree(obj);
+ err1:
+ module_put(type->owner);
++err_type:
++ nft_use_dec_restore(&table->use);
++
+ return err;
+ }
+
+@@ -5527,7 +5558,7 @@ void nf_tables_deactivate_flowtable(cons
+ case NFT_TRANS_PREPARE:
+ case NFT_TRANS_ABORT:
+ case NFT_TRANS_RELEASE:
+- flowtable->use--;
++ nft_use_dec(&flowtable->use);
+ /* fall through */
+ default:
+ return;
+@@ -5734,9 +5765,14 @@ static int nf_tables_newflowtable(struct
+
+ nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla);
+
++ if (!nft_use_inc(&table->use))
++ return -EMFILE;
++
+ flowtable = kzalloc(sizeof(*flowtable), GFP_KERNEL);
+- if (!flowtable)
+- return -ENOMEM;
++ if (!flowtable) {
++ err = -ENOMEM;
++ goto flowtable_alloc;
++ }
+
+ flowtable->table = table;
+ flowtable->handle = nf_tables_alloc_handle(table);
+@@ -5790,7 +5826,6 @@ static int nf_tables_newflowtable(struct
+ goto err6;
+
+ list_add_tail_rcu(&flowtable->list, &table->flowtables);
+- table->use++;
+
+ return 0;
+ err6:
+@@ -5808,6 +5843,9 @@ err2:
+ kfree(flowtable->name);
+ err1:
+ kfree(flowtable);
++flowtable_alloc:
++ nft_use_dec_restore(&table->use);
++
+ return err;
+ }
+
+@@ -6682,7 +6720,7 @@ static int nf_tables_commit(struct net *
+ */
+ if (nft_set_is_anonymous(nft_trans_set(trans)) &&
+ !list_empty(&nft_trans_set(trans)->bindings))
+- trans->ctx.table->use--;
++ nft_use_dec(&trans->ctx.table->use);
+
+ nf_tables_set_notify(&trans->ctx, nft_trans_set(trans),
+ NFT_MSG_NEWSET, GFP_KERNEL);
+@@ -6808,7 +6846,7 @@ static int __nf_tables_abort(struct net
+ kfree(nft_trans_chain_name(trans));
+ nft_trans_destroy(trans);
+ } else {
+- trans->ctx.table->use--;
++ nft_use_dec_restore(&trans->ctx.table->use);
+ nft_chain_del(trans->ctx.chain);
+ nf_tables_unregister_hook(trans->ctx.net,
+ trans->ctx.table,
+@@ -6816,25 +6854,25 @@ static int __nf_tables_abort(struct net
+ }
+ break;
+ case NFT_MSG_DELCHAIN:
+- trans->ctx.table->use++;
++ nft_use_inc_restore(&trans->ctx.table->use);
+ nft_clear(trans->ctx.net, trans->ctx.chain);
+ nft_trans_destroy(trans);
+ break;
+ case NFT_MSG_NEWRULE:
+- trans->ctx.chain->use--;
++ nft_use_dec_restore(&trans->ctx.chain->use);
+ list_del_rcu(&nft_trans_rule(trans)->list);
+ nft_rule_expr_deactivate(&trans->ctx,
+ nft_trans_rule(trans),
+ NFT_TRANS_ABORT);
+ break;
+ case NFT_MSG_DELRULE:
+- trans->ctx.chain->use++;
++ nft_use_inc_restore(&trans->ctx.chain->use);
+ nft_clear(trans->ctx.net, nft_trans_rule(trans));
+ nft_rule_expr_activate(&trans->ctx, nft_trans_rule(trans));
+ nft_trans_destroy(trans);
+ break;
+ case NFT_MSG_NEWSET:
+- trans->ctx.table->use--;
++ nft_use_dec_restore(&trans->ctx.table->use);
+ if (nft_trans_set_bound(trans)) {
+ nft_trans_destroy(trans);
+ break;
+@@ -6842,7 +6880,7 @@ static int __nf_tables_abort(struct net
+ list_del_rcu(&nft_trans_set(trans)->list);
+ break;
+ case NFT_MSG_DELSET:
+- trans->ctx.table->use++;
++ nft_use_inc_restore(&trans->ctx.table->use);
+ nft_clear(trans->ctx.net, nft_trans_set(trans));
+ nft_trans_destroy(trans);
+ break;
+@@ -6865,22 +6903,22 @@ static int __nf_tables_abort(struct net
+ nft_trans_destroy(trans);
+ break;
+ case NFT_MSG_NEWOBJ:
+- trans->ctx.table->use--;
++ nft_use_dec_restore(&trans->ctx.table->use);
+ list_del_rcu(&nft_trans_obj(trans)->list);
+ break;
+ case NFT_MSG_DELOBJ:
+- trans->ctx.table->use++;
++ nft_use_inc_restore(&trans->ctx.table->use);
+ nft_clear(trans->ctx.net, nft_trans_obj(trans));
+ nft_trans_destroy(trans);
+ break;
+ case NFT_MSG_NEWFLOWTABLE:
+- trans->ctx.table->use--;
++ nft_use_dec_restore(&trans->ctx.table->use);
+ list_del_rcu(&nft_trans_flowtable(trans)->list);
+ nft_unregister_flowtable_net_hooks(net,
+ nft_trans_flowtable(trans));
+ break;
+ case NFT_MSG_DELFLOWTABLE:
+- trans->ctx.table->use++;
++ nft_use_inc_restore(&trans->ctx.table->use);
+ nft_clear(trans->ctx.net, nft_trans_flowtable(trans));
+ nft_trans_destroy(trans);
+ break;
+@@ -7294,8 +7332,9 @@ static int nft_verdict_init(const struct
+ return PTR_ERR(chain);
+ if (nft_is_base_chain(chain))
+ return -EOPNOTSUPP;
++ if (!nft_use_inc(&chain->use))
++ return -EMFILE;
+
+- chain->use++;
+ data->verdict.chain = chain;
+ break;
+ }
+@@ -7307,10 +7346,13 @@ static int nft_verdict_init(const struct
+
+ static void nft_verdict_uninit(const struct nft_data *data)
+ {
++ struct nft_chain *chain;
++
+ switch (data->verdict.code) {
+ case NFT_JUMP:
+ case NFT_GOTO:
+- data->verdict.chain->use--;
++ chain = data->verdict.chain;
++ nft_use_dec(&chain->use);
+ break;
+ }
+ }
+@@ -7463,11 +7505,11 @@ int __nft_release_basechain(struct nft_c
+ nf_tables_unregister_hook(ctx->net, ctx->chain->table, ctx->chain);
+ list_for_each_entry_safe(rule, nr, &ctx->chain->rules, list) {
+ list_del(&rule->list);
+- ctx->chain->use--;
++ nft_use_dec(&ctx->chain->use);
+ nf_tables_rule_release(ctx, rule);
+ }
+ nft_chain_del(ctx->chain);
+- ctx->table->use--;
++ nft_use_dec(&ctx->table->use);
+ nf_tables_chain_destroy(ctx);
+
+ return 0;
+@@ -7496,29 +7538,29 @@ static void __nft_release_table(struct n
+ ctx.chain = chain;
+ list_for_each_entry_safe(rule, nr, &chain->rules, list) {
+ list_del(&rule->list);
+- chain->use--;
++ nft_use_dec(&chain->use);
+ nf_tables_rule_release(&ctx, rule);
+ }
+ }
+ list_for_each_entry_safe(flowtable, nf, &table->flowtables, list) {
+ list_del(&flowtable->list);
+- table->use--;
++ nft_use_dec(&table->use);
+ nf_tables_flowtable_destroy(flowtable);
+ }
+ list_for_each_entry_safe(set, ns, &table->sets, list) {
+ list_del(&set->list);
+- table->use--;
++ nft_use_dec(&table->use);
+ nft_set_destroy(set);
+ }
+ list_for_each_entry_safe(obj, ne, &table->objects, list) {
+ list_del(&obj->list);
+- table->use--;
++ nft_use_dec(&table->use);
+ nft_obj_destroy(&ctx, obj);
+ }
+ list_for_each_entry_safe(chain, nc, &table->chains, list) {
+ ctx.chain = chain;
+ nft_chain_del(chain);
+- table->use--;
++ nft_use_dec(&table->use);
+ nf_tables_chain_destroy(&ctx);
+ }
+ list_del(&table->list);
+--- a/net/netfilter/nft_flow_offload.c
++++ b/net/netfilter/nft_flow_offload.c
+@@ -169,8 +169,10 @@ static int nft_flow_offload_init(const s
+ if (IS_ERR(flowtable))
+ return PTR_ERR(flowtable);
+
++ if (!nft_use_inc(&flowtable->use))
++ return -EMFILE;
++
+ priv->flowtable = flowtable;
+- flowtable->use++;
+
+ return nf_ct_netns_get(ctx->net, ctx->family);
+ }
+@@ -189,7 +191,7 @@ static void nft_flow_offload_activate(co
+ {
+ struct nft_flow_offload *priv = nft_expr_priv(expr);
+
+- priv->flowtable->use++;
++ nft_use_inc_restore(&priv->flowtable->use);
+ }
+
+ static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
+--- a/net/netfilter/nft_objref.c
++++ b/net/netfilter/nft_objref.c
+@@ -43,8 +43,10 @@ static int nft_objref_init(const struct
+ if (IS_ERR(obj))
+ return -ENOENT;
+
++ if (!nft_use_inc(&obj->use))
++ return -EMFILE;
++
+ nft_objref_priv(expr) = obj;
+- obj->use++;
+
+ return 0;
+ }
+@@ -73,7 +75,7 @@ static void nft_objref_deactivate(const
+ if (phase == NFT_TRANS_COMMIT)
+ return;
+
+- obj->use--;
++ nft_use_dec(&obj->use);
+ }
+
+ static void nft_objref_activate(const struct nft_ctx *ctx,
+@@ -81,7 +83,7 @@ static void nft_objref_activate(const st
+ {
+ struct nft_object *obj = nft_objref_priv(expr);
+
+- obj->use++;
++ nft_use_inc_restore(&obj->use);
+ }
+
+ static struct nft_expr_type nft_objref_type;
projects / thirdparty / kernel / stable-queue.git / commitdiff
