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netfilter: nf_tables: report use refcount overflow 

[ Upstream commit 1689f25924 ]

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: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pablo Neira Ayuso 2023-06-28 16:24:27 +02:00 committed by Greg Kroah-Hartman
parent 9c1c1cc08b
commit e93cbd7efd
5 changed files with 141 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
include/net/netfilter/nf_tables.h
View File

@ -1211,6 +1211,29 @@ int __nft_release_basechain(struct nft_ctx *ctx);
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
*
@ -1296,8 +1319,8 @@ struct nft_object {
struct list_head list;
struct rhlist_head rhlhead;
struct nft_object_hash_key key;
u32 genmask:2,
use:30;
u32 genmask:2;
u32 use;
u64 handle;
u16 udlen;
u8 *udata;
@ -1399,8 +1422,8 @@ struct nft_flowtable {
char *name;
int hooknum;
int ops_len;
u32 genmask:2,
use:30;
u32 genmask:2;
u32 use;
u64 handle;
/* runtime data below here */
struct list_head hook_list ____cacheline_aligned;

163
net/netfilter/nf_tables_api.c
View File

@ -253,8 +253,10 @@ int nf_tables_bind_chain(const struct nft_ctx *ctx, struct nft_chain *chain)
if (chain->bound)
return -EBUSY;
if (!nft_use_inc(&chain->use))
return -EMFILE;
chain->bound = true;
chain->use++;
nft_chain_trans_bind(ctx, chain);
return 0;
@ -437,7 +439,7 @@ static int nft_delchain(struct nft_ctx *ctx)
if (IS_ERR(trans))
return PTR_ERR(trans);
ctx->table->use--;
nft_use_dec(&ctx->table->use);
nft_deactivate_next(ctx->net, ctx->chain);
return 0;
@ -476,7 +478,7 @@ nf_tables_delrule_deactivate(struct nft_ctx *ctx, struct nft_rule *rule)
/* 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;
@ -643,7 +645,7 @@ static int nft_delset(const struct nft_ctx *ctx, struct nft_set *set)
nft_map_deactivate(ctx, set);
nft_deactivate_next(ctx->net, set);
ctx->table->use--;
nft_use_dec(&ctx->table->use);
return err;
}
@ -675,7 +677,7 @@ static int nft_delobj(struct nft_ctx *ctx, struct nft_object *obj)
return err;
nft_deactivate_next(ctx->net, obj);
ctx->table->use--;
nft_use_dec(&ctx->table->use);
return err;
}
@ -710,7 +712,7 @@ static int nft_delflowtable(struct nft_ctx *ctx,
return err;
nft_deactivate_next(ctx->net, flowtable);
ctx->table->use--;
nft_use_dec(&ctx->table->use);
return err;
}
@ -2395,9 +2397,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
struct nft_chain *chain;
int err;
if (table->use == UINT_MAX)
return -EOVERFLOW;
if (nla[NFTA_CHAIN_HOOK]) {
struct nft_stats __percpu *stats = NULL;
struct nft_chain_hook hook = {};
@ -2493,6 +2492,11 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
if (err < 0)
goto err_destroy_chain;
if (!nft_use_inc(&table->use)) {
err = -EMFILE;
goto err_use;
}
trans = nft_trans_chain_add(ctx, NFT_MSG_NEWCHAIN);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
@ -2509,10 +2513,11 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
goto err_unregister_hook;
}
table->use++;
return 0;
err_unregister_hook:
nft_use_dec_restore(&table->use);
err_use:
nf_tables_unregister_hook(net, table, chain);
err_destroy_chain:
nf_tables_chain_destroy(ctx);
@ -3841,9 +3846,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
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);
@ -3937,6 +3939,11 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
}
}
if (!nft_use_inc(&chain->use)) {
err = -EMFILE;
goto err_release_rule;
}
if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
err = nft_delrule(&ctx, old_rule);
if (err < 0)
@ -3968,7 +3975,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
}
}
kvfree(expr_info);
chain->use++;
if (flow)
nft_trans_flow_rule(trans) = flow;
@ -3979,6 +3985,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
return 0;
err_destroy_flow_rule:
nft_use_dec_restore(&chain->use);
if (flow)
nft_flow_rule_destroy(flow);
err_release_rule:
@ -5015,9 +5022,15 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
alloc_size = sizeof(*set) + size + udlen;
if (alloc_size < size || alloc_size > INT_MAX)
return -ENOMEM;
if (!nft_use_inc(&table->use))
return -EMFILE;
set = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT);
if (!set)
return -ENOMEM;
if (!set) {
err = -ENOMEM;
goto err_alloc;
}
name = nla_strdup(nla[NFTA_SET_NAME], GFP_KERNEL_ACCOUNT);
if (!name) {
@ -5075,7 +5088,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
goto err_set_expr_alloc;
list_add_tail_rcu(&set->list, &table->sets);
table->use++;
return 0;
err_set_expr_alloc:
@ -5087,6 +5100,9 @@ err_set_init:
kfree(set->name);
err_set_name:
kvfree(set);
err_alloc:
nft_use_dec_restore(&table->use);
return err;
}
@ -5225,9 +5241,6 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
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;
@ -5255,10 +5268,12 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
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;
}
@ -5332,7 +5347,7 @@ void nf_tables_activate_set(const struct nft_ctx *ctx, struct nft_set *set)
nft_clear(ctx->net, set);
}
set->use++;
nft_use_inc_restore(&set->use);
}
EXPORT_SYMBOL_GPL(nf_tables_activate_set);
@ -5348,7 +5363,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
else
list_del_rcu(&binding->list);
set->use--;
nft_use_dec(&set->use);
break;
case NFT_TRANS_PREPARE:
if (nft_set_is_anonymous(set)) {
@ -5357,7 +5372,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
nft_deactivate_next(ctx->net, set);
}
set->use--;
nft_use_dec(&set->use);
return;
case NFT_TRANS_ABORT:
case NFT_TRANS_RELEASE:
@ -5365,7 +5380,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
set->flags & (NFT_SET_MAP | NFT_SET_OBJECT))
nft_map_deactivate(ctx, set);
set->use--;
nft_use_dec(&set->use);
fallthrough;
default:
nf_tables_unbind_set(ctx, set, binding,
@ -6134,7 +6149,7 @@ void nft_set_elem_destroy(const struct nft_set *set, void *elem,
nft_set_elem_expr_destroy(&ctx, nft_set_ext_expr(ext));
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);
@ -6636,8 +6651,16 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
set->objtype, genmask);
if (IS_ERR(obj)) {
err = PTR_ERR(obj);
obj = NULL;
goto err_parse_key_end;
}
if (!nft_use_inc(&obj->use)) {
err = -EMFILE;
obj = NULL;
goto err_parse_key_end;
}
err = nft_set_ext_add(&tmpl, NFT_SET_EXT_OBJREF);
if (err < 0)
goto err_parse_key_end;
@ -6706,10 +6729,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
if (flags)
*nft_set_ext_flags(ext) = flags;
if (obj) {
if (obj)
*nft_set_ext_obj(ext) = obj;
obj->use++;
}
if (ulen > 0) {
if (nft_set_ext_check(&tmpl, NFT_SET_EXT_USERDATA, ulen) < 0) {
err = -EINVAL;
@ -6774,12 +6796,13 @@ err_element_clash:
kfree(trans);
err_elem_free:
nf_tables_set_elem_destroy(ctx, set, elem.priv);
if (obj)
obj->use--;
err_parse_data:
if (nla[NFTA_SET_ELEM_DATA] != NULL)
nft_data_release(&elem.data.val, desc.type);
err_parse_key_end:
if (obj)
nft_use_dec_restore(&obj->use);
nft_data_release(&elem.key_end.val, NFT_DATA_VALUE);
err_parse_key:
nft_data_release(&elem.key.val, NFT_DATA_VALUE);
@ -6859,7 +6882,7 @@ void nft_data_hold(const struct nft_data *data, enum nft_data_types type)
case NFT_JUMP:
case NFT_GOTO:
chain = data->verdict.chain;
chain->use++;
nft_use_inc_restore(&chain->use);
break;
}
}
@ -6874,7 +6897,7 @@ static void nft_setelem_data_activate(const struct net *net,
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_setelem_data_deactivate(const struct net *net,
@ -6886,7 +6909,7 @@ static void nft_setelem_data_deactivate(const struct net *net,
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,
@ -7429,9 +7452,14 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
nft_ctx_init(&ctx, net, skb, info->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)) {
@ -7465,7 +7493,7 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
goto err_obj_ht;
list_add_tail_rcu(&obj->list, &table->objects);
table->use++;
return 0;
err_obj_ht:
/* queued in transaction log */
@ -7481,6 +7509,9 @@ err_strdup:
kfree(obj);
err_init:
module_put(type->owner);
err_type:
nft_use_dec_restore(&table->use);
return err;
}
@ -7882,7 +7913,7 @@ void nf_tables_deactivate_flowtable(const struct nft_ctx *ctx,
case NFT_TRANS_PREPARE:
case NFT_TRANS_ABORT:
case NFT_TRANS_RELEASE:
flowtable->use--;
nft_use_dec(&flowtable->use);
fallthrough;
default:
return;
@ -8236,9 +8267,14 @@ static int nf_tables_newflowtable(struct sk_buff *skb,
nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);
if (!nft_use_inc(&table->use))
return -EMFILE;
flowtable = kzalloc(sizeof(*flowtable), GFP_KERNEL_ACCOUNT);
if (!flowtable)
return -ENOMEM;
if (!flowtable) {
err = -ENOMEM;
goto flowtable_alloc;
}
flowtable->table = table;
flowtable->handle = nf_tables_alloc_handle(table);
@ -8293,7 +8329,6 @@ static int nf_tables_newflowtable(struct sk_buff *skb,
goto err5;
list_add_tail_rcu(&flowtable->list, &table->flowtables);
table->use++;
return 0;
err5:
@ -8310,6 +8345,9 @@ err2:
kfree(flowtable->name);
err1:
kfree(flowtable);
flowtable_alloc:
nft_use_dec_restore(&table->use);
return err;
}
@ -9680,7 +9718,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
*/
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);
@ -9910,7 +9948,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nft_trans_destroy(trans);
break;
}
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,
@ -9923,7 +9961,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
list_splice(&nft_trans_chain_hooks(trans),
&nft_trans_basechain(trans)->hook_list);
} else {
trans->ctx.table->use++;
nft_use_inc_restore(&trans->ctx.table->use);
nft_clear(trans->ctx.net, trans->ctx.chain);
}
nft_trans_destroy(trans);
@ -9933,7 +9971,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nft_trans_destroy(trans);
break;
}
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),
@ -9943,7 +9981,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
break;
case NFT_MSG_DELRULE:
case NFT_MSG_DESTROYRULE:
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));
if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD)
@ -9956,7 +9994,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nft_trans_destroy(trans);
break;
}
trans->ctx.table->use--;
nft_use_dec_restore(&trans->ctx.table->use);
if (nft_trans_set_bound(trans)) {
nft_trans_destroy(trans);
break;
@ -9965,7 +10003,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
break;
case NFT_MSG_DELSET:
case NFT_MSG_DESTROYSET:
trans->ctx.table->use++;
nft_use_inc_restore(&trans->ctx.table->use);
nft_clear(trans->ctx.net, nft_trans_set(trans));
if (nft_trans_set(trans)->flags & (NFT_SET_MAP | NFT_SET_OBJECT))
nft_map_activate(&trans->ctx, nft_trans_set(trans));
@ -10009,13 +10047,13 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nft_obj_destroy(&trans->ctx, nft_trans_obj_newobj(trans));
nft_trans_destroy(trans);
} else {
trans->ctx.table->use--;
nft_use_dec_restore(&trans->ctx.table->use);
nft_obj_del(nft_trans_obj(trans));
}
break;
case NFT_MSG_DELOBJ:
case NFT_MSG_DESTROYOBJ:
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;
@ -10024,7 +10062,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nft_unregister_flowtable_net_hooks(net,
&nft_trans_flowtable_hooks(trans));
} else {
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)->hook_list);
@ -10036,7 +10074,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
list_splice(&nft_trans_flowtable_hooks(trans),
&nft_trans_flowtable(trans)->hook_list);
} else {
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);
@ -10486,8 +10524,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data,
if (desc->flags & NFT_DATA_DESC_SETELEM &&
chain->flags & NFT_CHAIN_BINDING)
return -EINVAL;
if (!nft_use_inc(&chain->use))
return -EMFILE;
chain->use++;
data->verdict.chain = chain;
break;
}
@ -10505,7 +10544,7 @@ static void nft_verdict_uninit(const struct nft_data *data)
case NFT_JUMP:
case NFT_GOTO:
chain = data->verdict.chain;
chain->use--;
nft_use_dec(&chain->use);
break;
}
}
@ -10674,11 +10713,11 @@ int __nft_release_basechain(struct nft_ctx *ctx)
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;
@ -10728,18 +10767,18 @@ static void __nft_release_table(struct net *net, struct nft_table *table)
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);
if (set->flags & (NFT_SET_MAP | NFT_SET_OBJECT))
nft_map_deactivate(&ctx, set);
@ -10747,13 +10786,13 @@ static void __nft_release_table(struct net *net, struct nft_table *table)
}
list_for_each_entry_safe(obj, ne, &table->objects, list) {
nft_obj_del(obj);
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);
}
nf_tables_table_destroy(&ctx);

6
net/netfilter/nft_flow_offload.c
View File

@ -404,8 +404,10 @@ static int nft_flow_offload_init(const struct nft_ctx *ctx,
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);
}
@ -424,7 +426,7 @@ static void nft_flow_offload_activate(const struct nft_ctx *ctx,
{
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,

8
net/netfilter/nft_immediate.c
View File

@ -159,7 +159,7 @@ static void nft_immediate_deactivate(const struct nft_ctx *ctx,
default:
nft_chain_del(chain);
chain->bound = false;
chain->table->use--;
nft_use_dec(&chain->table->use);
break;
}
break;
@ -198,7 +198,7 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx,
* let the transaction records release this chain and its rules.
*/
if (chain->bound) {
chain->use--;
nft_use_dec(&chain->use);
break;
}
@ -206,9 +206,9 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx,
chain_ctx = *ctx;
chain_ctx.chain = chain;
chain->use--;
nft_use_dec(&chain->use);
list_for_each_entry_safe(rule, n, &chain->rules, list) {
chain->use--;
nft_use_dec(&chain->use);
list_del(&rule->list);
nf_tables_rule_destroy(&chain_ctx, rule);
}

8
net/netfilter/nft_objref.c
View File

@ -41,8 +41,10 @@ static int nft_objref_init(const struct nft_ctx *ctx,
if (IS_ERR(obj))
return -ENOENT;
if (!nft_use_inc(&obj->use))
return -EMFILE;
nft_objref_priv(expr) = obj;
obj->use++;
return 0;
}
@ -72,7 +74,7 @@ static void nft_objref_deactivate(const struct nft_ctx *ctx,
if (phase == NFT_TRANS_COMMIT)
return;
obj->use--;
nft_use_dec(&obj->use);
}
static void nft_objref_activate(const struct nft_ctx *ctx,
@ -80,7 +82,7 @@ static void nft_objref_activate(const struct nft_ctx *ctx,
{
struct nft_object *obj = nft_objref_priv(expr);
obj->use++;
nft_use_inc_restore(&obj->use);
}
static const struct nft_expr_ops nft_objref_ops = {