netfilter: nf_tables: bogus EBUSY in helper removal from transaction

commit 8ffcd32f64633926163cdd07a7d295c500a947d1 upstream.

Proper use counter updates when activating and deactivating the object,
otherwise, this hits bogus EBUSY error.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Laura Garcia <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c
index 49a067a67e7231bc28649aa6fa2edd54185013ba..5deb997db9bbb9529cb6b29f9a8298cda459844e 100644 (file)
--- a/net/netfilter/nft_objref.c
+++ b/net/netfilter/nft_objref.c
@@ -64,21 +64,34 @@ static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr)
        return -1;
 }
 
-static void nft_objref_destroy(const struct nft_ctx *ctx,
-                              const struct nft_expr *expr)
+static void nft_objref_deactivate(const struct nft_ctx *ctx,
+                                 const struct nft_expr *expr,
+                                 enum nft_trans_phase phase)
 {
        struct nft_object *obj = nft_objref_priv(expr);
 
+       if (phase == NFT_TRANS_COMMIT)
+               return;
+
        obj->use--;
 }
 
+static void nft_objref_activate(const struct nft_ctx *ctx,
+                               const struct nft_expr *expr)
+{
+       struct nft_object *obj = nft_objref_priv(expr);
+
+       obj->use++;
+}
+
 static struct nft_expr_type nft_objref_type;
 static const struct nft_expr_ops nft_objref_ops = {
        .type           = &nft_objref_type,
        .size           = NFT_EXPR_SIZE(sizeof(struct nft_object *)),
        .eval           = nft_objref_eval,
        .init           = nft_objref_init,
-       .destroy        = nft_objref_destroy,
+       .activate       = nft_objref_activate,
+       .deactivate     = nft_objref_deactivate,
        .dump           = nft_objref_dump,
 };