netfilter: nf_tables: unbind set in rule from commit path

Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.

This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.

Moreover, this patch adds the unbind step to deliver the event from the
commit path.  This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.

This patch removes the assumption that both activate and deactivate
callbacks need to be provided.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Mikhail Morfikov <mmorfikov@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 841835a387e1..b4984bbbe157 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -469,9 +469,7 @@ struct nft_set_binding {
 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,
-			  struct nft_set_binding *binding);
-void nf_tables_rebind_set(const struct nft_ctx *ctx, struct nft_set *set,
-			  struct nft_set_binding *binding);
+			  struct nft_set_binding *binding, bool commit);
 void nf_tables_destroy_set(const struct nft_ctx *ctx, struct nft_set *set);
 
 /**
@@ -721,6 +719,13 @@ struct nft_expr_type {
 #define NFT_EXPR_STATEFUL		0x1
 #define NFT_EXPR_GC			0x2
 
+enum nft_trans_phase {
+	NFT_TRANS_PREPARE,
+	NFT_TRANS_ABORT,
+	NFT_TRANS_COMMIT,
+	NFT_TRANS_RELEASE
+};
+
 /**
  *	struct nft_expr_ops - nf_tables expression operations
  *
@@ -750,7 +755,8 @@ struct nft_expr_ops {
 	void				(*activate)(const struct nft_ctx *ctx,
 						    const struct nft_expr *expr);
 	void				(*deactivate)(const struct nft_ctx *ctx,
-						      const struct nft_expr *expr);
+						      const struct nft_expr *expr,
+						      enum nft_trans_phase phase);
 	void				(*destroy)(const struct nft_ctx *ctx,
 						   const struct nft_expr *expr);
 	void				(*destroy_clone)(const struct nft_ctx *ctx,
@@ -1323,12 +1329,15 @@ struct nft_trans_rule {
 struct nft_trans_set {
 	struct nft_set			*set;
 	u32				set_id;
+	bool				bound;
 };
 
 #define nft_trans_set(trans)	\
 	(((struct nft_trans_set *)trans->data)->set)
 #define nft_trans_set_id(trans)	\
 	(((struct nft_trans_set *)trans->data)->set_id)
+#define nft_trans_set_bound(trans)	\
+	(((struct nft_trans_set *)trans->data)->bound)
 
 struct nft_trans_chain {
 	bool				update;