netfilter: nf_tables: bogus EBUSY when deleting set after flush
[ Upstream commit 273fe3f1006ea5ebc63d6729e43e8e45e32b256a ]
Set deletion after flush coming in the same batch results in EBUSY. Add
set use counter to track the number of references to this set from
rules. We cannot rely on the list of bindings for this since such list
is still populated from the preparation phase.
Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index e5f879e..f2be5d0 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -382,6 +382,7 @@
* @dtype: data type (verdict or numeric type defined by userspace)
* @objtype: object type (see NFT_OBJECT_* definitions)
* @size: maximum set size
+ * @use: number of rules references to this set
* @nelems: number of elements
* @ndeact: number of deactivated elements queued for removal
* @timeout: default timeout value in jiffies
@@ -407,6 +408,7 @@
u32 dtype;
u32 objtype;
u32 size;
+ u32 use;
atomic_t nelems;
u32 ndeact;
u64 timeout;
@@ -467,6 +469,10 @@
u32 flags;
};
+enum nft_trans_phase;
+void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
+ struct nft_set_binding *binding,
+ enum nft_trans_phase phase);
int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
struct nft_set_binding *binding);
void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 959f123..1af5411 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3585,6 +3585,9 @@
static void nft_set_destroy(struct nft_set *set)
{
+ if (WARN_ON(set->use > 0))
+ return;
+
set->ops->destroy(set);
module_put(to_set_type(set->ops)->owner);
kfree(set->name);
@@ -3625,7 +3628,7 @@
NL_SET_BAD_ATTR(extack, attr);
return PTR_ERR(set);
}
- if (!list_empty(&set->bindings) ||
+ if (set->use ||
(nlh->nlmsg_flags & NLM_F_NONREC && atomic_read(&set->nelems) > 0)) {
NL_SET_BAD_ATTR(extack, attr);
return -EBUSY;
@@ -3655,6 +3658,9 @@
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;
@@ -3682,6 +3688,7 @@
binding->chain = ctx->chain;
list_add_tail_rcu(&binding->list, &set->bindings);
nft_set_trans_bind(ctx, set);
+ set->use++;
return 0;
}
@@ -3701,6 +3708,25 @@
}
EXPORT_SYMBOL_GPL(nf_tables_unbind_set);
+void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
+ struct nft_set_binding *binding,
+ enum nft_trans_phase phase)
+{
+ switch (phase) {
+ case NFT_TRANS_PREPARE:
+ set->use--;
+ return;
+ case NFT_TRANS_ABORT:
+ case NFT_TRANS_RELEASE:
+ set->use--;
+ /* fall through */
+ default:
+ nf_tables_unbind_set(ctx, set, binding,
+ phase == NFT_TRANS_COMMIT);
+ }
+}
+EXPORT_SYMBOL_GPL(nf_tables_deactivate_set);
+
void nf_tables_destroy_set(const struct nft_ctx *ctx, struct nft_set *set)
{
if (list_empty(&set->bindings) && nft_set_is_anonymous(set))
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index f1172f9..eb7f9a5 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -241,11 +241,15 @@
{
struct nft_dynset *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
- return;
+ nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
+}
- nf_tables_unbind_set(ctx, priv->set, &priv->binding,
- phase == NFT_TRANS_COMMIT);
+static void nft_dynset_activate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ struct nft_dynset *priv = nft_expr_priv(expr);
+
+ priv->set->use++;
}
static void nft_dynset_destroy(const struct nft_ctx *ctx,
@@ -293,6 +297,7 @@
.eval = nft_dynset_eval,
.init = nft_dynset_init,
.destroy = nft_dynset_destroy,
+ .activate = nft_dynset_activate,
.deactivate = nft_dynset_deactivate,
.dump = nft_dynset_dump,
};
diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c
index 14496da..161c345 100644
--- a/net/netfilter/nft_lookup.c
+++ b/net/netfilter/nft_lookup.c
@@ -127,11 +127,15 @@
{
struct nft_lookup *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
- return;
+ nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
+}
- nf_tables_unbind_set(ctx, priv->set, &priv->binding,
- phase == NFT_TRANS_COMMIT);
+static void nft_lookup_activate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ struct nft_lookup *priv = nft_expr_priv(expr);
+
+ priv->set->use++;
}
static void nft_lookup_destroy(const struct nft_ctx *ctx,
@@ -222,6 +226,7 @@
.size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
.eval = nft_lookup_eval,
.init = nft_lookup_init,
+ .activate = nft_lookup_activate,
.deactivate = nft_lookup_deactivate,
.destroy = nft_lookup_destroy,
.dump = nft_lookup_dump,
diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c
index ae178e9..d8737c1 100644
--- a/net/netfilter/nft_objref.c
+++ b/net/netfilter/nft_objref.c
@@ -161,11 +161,15 @@
{
struct nft_objref_map *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
- return;
+ nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
+}
- nf_tables_unbind_set(ctx, priv->set, &priv->binding,
- phase == NFT_TRANS_COMMIT);
+static void nft_objref_map_activate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ struct nft_objref_map *priv = nft_expr_priv(expr);
+
+ priv->set->use++;
}
static void nft_objref_map_destroy(const struct nft_ctx *ctx,
@@ -182,6 +186,7 @@
.size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
.eval = nft_objref_map_eval,
.init = nft_objref_map_init,
+ .activate = nft_objref_map_activate,
.deactivate = nft_objref_map_deactivate,
.destroy = nft_objref_map_destroy,
.dump = nft_objref_map_dump,