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 <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> --- v2: object maps also need an update. include/net/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 2 +- net/netfilter/nft_lookup.c | 17 ++++++++++++++++- net/netfilter/nft_objref.c | 17 ++++++++++++++++- 4 files changed, 35 insertions(+), 3 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..282373d7c083 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; diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c index 14496da5141d..ac65f1a4e076 100644 --- a/net/netfilter/nft_lookup.c +++ b/net/netfilter/nft_lookup.c @@ -111,12 +111,16 @@ static int nft_lookup_init(const struct nft_ctx *ctx, } else if (set->flags & NFT_SET_MAP) return -EINVAL; + if (set->use == UINT_MAX) + return -EOVERFLOW; + priv->binding.flags = set->flags & NFT_SET_MAP; err = nf_tables_bind_set(ctx, set, &priv->binding); if (err < 0) return err; + set->use++; priv->set = set; return 0; } @@ -127,13 +131,23 @@ 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 +236,7 @@ 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..ee22698f2711 100644 --- a/net/netfilter/nft_objref.c +++ b/net/netfilter/nft_objref.c @@ -131,12 +131,16 @@ static int nft_objref_map_init(const struct nft_ctx *ctx, if (err < 0) return err; + if (set->use == UINT_MAX) + return -EOVERFLOW; + priv->binding.flags = set->flags & NFT_SET_OBJECT; err = nf_tables_bind_set(ctx, set, &priv->binding); if (err < 0) return err; + set->use++; priv->set = set; return 0; } @@ -161,13 +165,23 @@ 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 +196,7 @@ 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
