[LTS 9.2] netfilter: CVE-2024-27017, CVE-2024-27012 bugfixes

include/net/netfilter/nf_tables.h

@@ -274,9 +274,23 @@ static inline void *nft_elem_priv_cast(const struct nft_elem_priv *priv)
 	return (void *)priv;
 }
 
+
+/**
+ * enum nft_iter_type - nftables set iterator type
+ *
+ * @NFT_ITER_READ: read-only iteration over set elements
+ * @NFT_ITER_UPDATE: iteration under mutex to update set element state
+ */
+enum nft_iter_type {
+	NFT_ITER_UNSPEC,
+	NFT_ITER_READ,
+	NFT_ITER_UPDATE,
+};
+
 struct nft_set;
 struct nft_set_iter {
 	u8		genmask;
+	enum nft_iter_type type:8;
 	unsigned int	count;
 	unsigned int	skip;
 	int		err;

net/netfilter/nf_tables_api.c

@@ -591,6 +591,12 @@ static int nft_mapelem_deactivate(const struct nft_ctx *ctx,
 				  const struct nft_set_iter *iter,
 				  struct nft_set_elem *elem)
 {
+	struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
+
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
+	nft_set_elem_change_active(ctx->net, set, ext);
 	nft_setelem_data_deactivate(ctx->net, set, elem);
 
 	return 0;
@@ -615,6 +621,7 @@ static void nft_map_catchall_deactivate(const struct nft_ctx *ctx,
 		if (!nft_set_elem_active(ext, genmask))
 			continue;
 
+		nft_set_elem_change_active(ctx->net, set, ext);
 		elem.priv = catchall->elem;
 		nft_setelem_data_deactivate(ctx->net, set, &elem);
 		break;
@@ -625,6 +632,7 @@ static void nft_map_deactivate(const struct nft_ctx *ctx, struct nft_set *set)
 {
 	struct nft_set_iter iter = {
 		.genmask	= nft_genmask_next(ctx->net),
+		.type		= NFT_ITER_UPDATE,
 		.fn		= nft_mapelem_deactivate,
 	};
 
@@ -3483,6 +3491,9 @@ int nft_setelem_validate(const struct nft_ctx *ctx, struct nft_set *set,
 	const struct nft_data *data;
 	int err;
 
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) &&
 	    *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END)
 		return 0;
@@ -3506,19 +3517,21 @@ int nft_setelem_validate(const struct nft_ctx *ctx, struct nft_set *set,
 
 int nft_set_catchall_validate(const struct nft_ctx *ctx, struct nft_set *set)
 {
-	u8 genmask = nft_genmask_next(ctx->net);
+	struct nft_set_iter dummy_iter = {
+		.genmask	= nft_genmask_next(ctx->net),
+	};
 	struct nft_set_elem_catchall *catchall;
 	struct nft_set_elem elem;
 	struct nft_set_ext *ext;
 	int ret = 0;
 
 	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (!nft_set_elem_active(ext, genmask))
+		if (!nft_set_elem_active(ext, dummy_iter.genmask))
 			continue;
 
 		elem.priv = catchall->elem;
-		ret = nft_setelem_validate(ctx, set, NULL, &elem);
+		ret = nft_setelem_validate(ctx, set, &dummy_iter, &elem);
 		if (ret < 0)
 			return ret;
 	}
@@ -4995,6 +5008,11 @@ static int nf_tables_bind_check_setelem(const struct nft_ctx *ctx,
 					const struct nft_set_iter *iter,
 					struct nft_set_elem *elem)
 {
+	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
+
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
 	return nft_setelem_data_validate(ctx, set, elem);
 }
 
@@ -5041,6 +5059,7 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 		}
 
 		iter.genmask	= nft_genmask_next(ctx->net);
+		iter.type	= NFT_ITER_UPDATE;
 		iter.skip 	= 0;
 		iter.count	= 0;
 		iter.err	= 0;
@@ -5088,6 +5107,13 @@ static int nft_mapelem_activate(const struct nft_ctx *ctx,
 				const struct nft_set_iter *iter,
 				struct nft_set_elem *elem)
 {
+	struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
+
+	/* called from abort path, reverse check to undo changes. */
+	if (nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
+	nft_clear(ctx->net, ext);
 	nft_setelem_data_activate(ctx->net, set, elem);
 
 	return 0;
@@ -5106,6 +5132,7 @@ static void nft_map_catchall_activate(const struct nft_ctx *ctx,
 		if (!nft_set_elem_active(ext, genmask))
 			continue;
 
+		nft_clear(ctx->net, ext);
 		elem.priv = catchall->elem;
 		nft_setelem_data_activate(ctx->net, set, &elem);
 		break;
@@ -5116,6 +5143,7 @@ static void nft_map_activate(const struct nft_ctx *ctx, struct nft_set *set)
 {
 	struct nft_set_iter iter = {
 		.genmask	= nft_genmask_next(ctx->net),
+		.type		= NFT_ITER_UPDATE,
 		.fn		= nft_mapelem_activate,
 	};
 
@@ -5377,6 +5405,9 @@ static int nf_tables_dump_setelem(const struct nft_ctx *ctx,
 	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 	struct nft_set_dump_args *args;
 
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
 	if (nft_set_elem_expired(ext) || nft_set_elem_is_dead(ext))
 		return 0;
 
@@ -5473,6 +5504,7 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
 	args.cb			= cb;
 	args.skb		= skb;
 	args.iter.genmask	= nft_genmask_cur(net);
+	args.iter.type		= NFT_ITER_READ;
 	args.iter.skip		= cb->args[0];
 	args.iter.count		= 0;
 	args.iter.err		= 0;
@@ -6109,7 +6141,7 @@ static void nft_setelem_activate(struct net *net, struct nft_set *set,
 	struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 
 	if (nft_setelem_is_catchall(set, elem)) {
-		nft_set_elem_change_active(net, set, ext);
+		nft_clear(net, ext);
 	} else {
 		set->ops->activate(net, set, elem);
 	}
@@ -6783,8 +6815,12 @@ static int nft_setelem_flush(const struct nft_ctx *ctx,
 			     const struct nft_set_iter *iter,
 			     struct nft_set_elem *elem)
 {
+	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 	struct nft_trans *trans;
 
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
 	trans = nft_trans_alloc_gfp(ctx, NFT_MSG_DELSETELEM,
 				    sizeof(struct nft_trans_elem), GFP_ATOMIC);
 	if (!trans)
@@ -6848,6 +6884,7 @@ static int nft_set_flush(struct nft_ctx *ctx, struct nft_set *set, u8 genmask)
 {
 	struct nft_set_iter iter = {
 		.genmask	= genmask,
+		.type		= NFT_ITER_UPDATE,
 		.fn		= nft_setelem_flush,
 	};
 
@@ -10051,6 +10088,9 @@ static int nf_tables_loop_check_setelem(const struct nft_ctx *ctx,
 {
 	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 
+	if (!nft_set_elem_active(ext, iter->genmask))
+		return 0;
+
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) &&
 	    *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END)
 		return 0;
@@ -10132,6 +10172,7 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
 				continue;
 
 			iter.genmask	= nft_genmask_next(ctx->net);
+			iter.type	= NFT_ITER_UPDATE;
 			iter.skip 	= 0;
 			iter.count	= 0;
 			iter.err	= 0;

net/netfilter/nft_lookup.c

@@ -217,6 +217,7 @@ static int nft_lookup_validate(const struct nft_ctx *ctx,
 		return 0;
 
 	iter.genmask	= nft_genmask_next(ctx->net);
+	iter.type	= NFT_ITER_UPDATE;
 	iter.skip	= 0;
 	iter.count	= 0;
 	iter.err	= 0;

net/netfilter/nft_set_bitmap.c

@@ -173,7 +173,7 @@ static void nft_bitmap_activate(const struct net *net,
 	nft_bitmap_location(set, nft_set_ext_key(&be->ext), &idx, &off);
 	/* Enter 11 state. */
 	priv->bitmap[idx] |= (genmask << off);
-	nft_set_elem_change_active(net, set, &be->ext);
+	nft_clear(net, &be->ext);
 }
 
 static void nft_bitmap_flush(const struct net *net,
@@ -224,8 +224,6 @@ static void nft_bitmap_walk(const struct nft_ctx *ctx,
 	list_for_each_entry_rcu(be, &priv->list, head) {
 		if (iter->count < iter->skip)
 			goto cont;
-		if (!nft_set_elem_active(&be->ext, iter->genmask))
-			goto cont;
 
 		elem.priv = &be->priv;
 

net/netfilter/nft_set_hash.c

@@ -196,7 +196,7 @@ static void nft_rhash_activate(const struct net *net, const struct nft_set *set,
 {
 	struct nft_rhash_elem *he = nft_elem_priv_cast(elem->priv);
 
-	nft_set_elem_change_active(net, set, &he->ext);
+	nft_clear(net, &he->ext);
 }
 
 static void nft_rhash_flush(const struct net *net,
@@ -283,8 +283,6 @@ static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set,
 
 		if (iter->count < iter->skip)
 			goto cont;
-		if (!nft_set_elem_active(&he->ext, iter->genmask))
-			goto cont;
 
 		elem.priv = &he->priv;
 
@@ -612,7 +610,7 @@ static void nft_hash_activate(const struct net *net, const struct nft_set *set,
 {
 	struct nft_hash_elem *he = nft_elem_priv_cast(elem->priv);
 
-	nft_set_elem_change_active(net, set, &he->ext);
+	nft_clear(net, &he->ext);
 }
 
 static void nft_hash_flush(const struct net *net,
@@ -666,8 +664,6 @@ static void nft_hash_walk(const struct nft_ctx *ctx, struct nft_set *set,
 		hlist_for_each_entry_rcu(he, &priv->table[i], node) {
 			if (iter->count < iter->skip)
 				goto cont;
-			if (!nft_set_elem_active(&he->ext, iter->genmask))
-				goto cont;
 
 			elem.priv = &he->priv;
 

net/netfilter/nft_set_pipapo.c

@@ -1754,7 +1754,7 @@ static void nft_pipapo_activate(const struct net *net,
 {
 	struct nft_pipapo_elem *e = nft_elem_priv_cast(elem->priv);
 
-	nft_set_elem_change_active(net, set, &e->ext);
+	nft_clear(net, &e->ext);
 }
 
 /**
@@ -2021,13 +2021,15 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
 			    struct nft_set_iter *iter)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
-	struct net *net = read_pnet(&set->net);
 	struct nft_pipapo_match *m;
 	struct nft_pipapo_field *f;
 	int i, r;
 
+	WARN_ON_ONCE(iter->type != NFT_ITER_READ &&
+		     iter->type != NFT_ITER_UPDATE);
+
 	rcu_read_lock();
-	if (iter->genmask == nft_genmask_cur(net))
+	if (iter->type == NFT_ITER_READ)
 		m = rcu_dereference(priv->match);
 	else
 		m = priv->clone;
@@ -2050,9 +2052,6 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
 
 		e = f->mt[r].e;
 
-		if (!nft_set_elem_active(&e->ext, iter->genmask))
-			goto cont;
-
 		elem.priv = &e->priv;
 
 		iter->err = iter->fn(ctx, set, iter, &elem);

net/netfilter/nft_set_rbtree.c

@@ -530,7 +530,7 @@ static void nft_rbtree_activate(const struct net *net,
 {
 	struct nft_rbtree_elem *rbe = nft_elem_priv_cast(elem->priv);
 
-	nft_set_elem_change_active(net, set, &rbe->ext);
+	nft_clear(net, &rbe->ext);
 }
 
 static void nft_rbtree_flush(const struct net *net,
@@ -596,8 +596,6 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx,
 
 		if (iter->count < iter->skip)
 			goto cont;
-		if (!nft_set_elem_active(&rbe->ext, iter->genmask))
-			goto cont;
 
 		elem.priv = &rbe->priv;