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@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
v3: Consolidate set->use bump and overflow check from nf_tables_bind_set().
Update dynset too.
include/net/netfilter/nf_tables.h | 2 ++
net/netfilter/nf_tables_api.c | 6 +++++-
net/netfilter/nft_dynset.c | 13 ++++++++++++-
net/netfilter/nft_lookup.c | 13 ++++++++++++-
net/netfilter/nft_objref.c | 13 ++++++++++++-
5 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 3d58acf94dd2..d594ad758219 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -382,6 +382,7 @@ void nft_unregister_set(struct nft_set_type *type);
* @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 @@ struct nft_set {
u32 dtype;
u32 objtype;
u32 size;
+ u32 use;
atomic_t nelems;
u32 ndeact;
u64 timeout;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e1724f9d8b9d..295a5847f5ef 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3654,7 +3654,7 @@ static int nf_tables_delset(struct net *net, struct sock *nlsk,
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;
@@ -3684,6 +3684,9 @@ 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;
@@ -3711,6 +3714,7 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
binding->chain = ctx->chain;
list_add_tail_rcu(&binding->list, &set->bindings);
nft_set_trans_bind(ctx, set);
+ set->use++;
return 0;
}
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index f1172f99752b..2437c718ab15 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -241,13 +241,23 @@ static void nft_dynset_deactivate(const struct nft_ctx *ctx,
{
struct nft_dynset *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
+ if (phase == NFT_TRANS_PREPARE) {
+ priv->set->use--;
return;
+ }
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,
const struct nft_expr *expr)
{
@@ -293,6 +303,7 @@ static const struct nft_expr_ops nft_dynset_ops = {
.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 14496da5141d..ed2e8d8a38c1 100644
--- a/net/netfilter/nft_lookup.c
+++ b/net/netfilter/nft_lookup.c
@@ -127,13 +127,23 @@ static void nft_lookup_deactivate(const struct nft_ctx *ctx,
{
struct nft_lookup *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
+ if (phase == NFT_TRANS_PREPARE) {
+ priv->set->use--;
return;
+ }
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,
const struct nft_expr *expr)
{
@@ -222,6 +232,7 @@ static const struct nft_expr_ops nft_lookup_ops = {
.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 ae178e914486..9815a248502b 100644
--- a/net/netfilter/nft_objref.c
+++ b/net/netfilter/nft_objref.c
@@ -161,13 +161,23 @@ static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
{
struct nft_objref_map *priv = nft_expr_priv(expr);
- if (phase == NFT_TRANS_PREPARE)
+ if (phase == NFT_TRANS_PREPARE) {
+ priv->set->use--;
return;
+ }
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,
const struct nft_expr *expr)
{
@@ -182,6 +192,7 @@ static const struct nft_expr_ops nft_objref_map_ops = {
.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,
--
2.11.0
