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[SRU,OEM-5.17,OEM-6.0,1/3] netfilter: nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain

Message ID 20230803183103.676567-2-cascardo@canonical.com
State New
Headers show
Series [SRU,OEM-5.17,OEM-6.0,1/3] netfilter: nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain | expand

Commit Message

Thadeu Lima de Souza Cascardo Aug. 3, 2023, 6:31 p.m. UTC 
From: Pablo Neira Ayuso <pablo@netfilter.org>

Add a new state to deal with rule expressions deactivation from the
newrule error path, otherwise the anonymous set remains in the list in
inactive state for the next generation. Mark the set/chain transaction
as unbound so the abort path releases this object, set it as inactive in
the next generation so it is not reachable anymore from this transaction
and reference counter is dropped.

Fixes: 1240eb93f061 ("netfilter: nf_tables: incorrect error path handling with NFT_MSG_NEWRULE")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit 26b5a5712eb85e253724e56a54c17f8519bd8e4e)
CVE-2023-4015
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
---
 include/net/netfilter/nf_tables.h |  2 ++
 net/netfilter/nf_tables_api.c     | 45 ++++++++++++++++++++++++++-----
 net/netfilter/nft_immediate.c     |  3 +++
 3 files changed, 43 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 89ab811c31d4..18d996717e4f 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -879,6 +879,7 @@  struct nft_expr_type {
 
 enum nft_trans_phase {
 	NFT_TRANS_PREPARE,
+	NFT_TRANS_PREPARE_ERROR,
 	NFT_TRANS_ABORT,
 	NFT_TRANS_COMMIT,
 	NFT_TRANS_RELEASE
@@ -1069,6 +1070,7 @@  struct nft_chain {
 
 int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain);
 int nf_tables_bind_chain(const struct nft_ctx *ctx, struct nft_chain *chain);
+void nf_tables_unbind_chain(const struct nft_ctx *ctx, struct nft_chain *chain);
 
 enum nft_chain_types {
 	NFT_CHAIN_T_DEFAULT = 0,
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 5272f54046d7..ea4713f74b4a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -171,7 +171,8 @@  static void nft_trans_destroy(struct nft_trans *trans)
 	kfree(trans);
 }
 
-static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set)
+static void __nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set,
+				 bool bind)
 {
 	struct nftables_pernet *nft_net;
 	struct net *net = ctx->net;
@@ -185,17 +186,28 @@  static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set)
 		switch (trans->msg_type) {
 		case NFT_MSG_NEWSET:
 			if (nft_trans_set(trans) == set)
-				nft_trans_set_bound(trans) = true;
+				nft_trans_set_bound(trans) = bind;
 			break;
 		case NFT_MSG_NEWSETELEM:
 			if (nft_trans_elem_set(trans) == set)
-				nft_trans_elem_set_bound(trans) = true;
+				nft_trans_elem_set_bound(trans) = bind;
 			break;
 		}
 	}
 }
 
-static void nft_chain_trans_bind(const struct nft_ctx *ctx, struct nft_chain *chain)
+static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set)
+{
+	return __nft_set_trans_bind(ctx, set, true);
+}
+
+static void nft_set_trans_unbind(const struct nft_ctx *ctx, struct nft_set *set)
+{
+	return __nft_set_trans_bind(ctx, set, false);
+}
+
+static void __nft_chain_trans_bind(const struct nft_ctx *ctx,
+				   struct nft_chain *chain, bool bind)
 {
 	struct nftables_pernet *nft_net;
 	struct net *net = ctx->net;
@@ -209,16 +221,22 @@  static void nft_chain_trans_bind(const struct nft_ctx *ctx, struct nft_chain *ch
 		switch (trans->msg_type) {
 		case NFT_MSG_NEWCHAIN:
 			if (nft_trans_chain(trans) == chain)
-				nft_trans_chain_bound(trans) = true;
+				nft_trans_chain_bound(trans) = bind;
 			break;
 		case NFT_MSG_NEWRULE:
 			if (trans->ctx.chain == chain)
-				nft_trans_rule_bound(trans) = true;
+				nft_trans_rule_bound(trans) = bind;
 			break;
 		}
 	}
 }
 
+static void nft_chain_trans_bind(const struct nft_ctx *ctx,
+				 struct nft_chain *chain)
+{
+	__nft_chain_trans_bind(ctx, chain, true);
+}
+
 int nf_tables_bind_chain(const struct nft_ctx *ctx, struct nft_chain *chain)
 {
 	if (!nft_chain_binding(chain))
@@ -237,6 +255,11 @@  int nf_tables_bind_chain(const struct nft_ctx *ctx, struct nft_chain *chain)
 	return 0;
 }
 
+void nf_tables_unbind_chain(const struct nft_ctx *ctx, struct nft_chain *chain)
+{
+	__nft_chain_trans_bind(ctx, chain, false);
+}
+
 static int nft_netdev_register_hooks(struct net *net,
 				     struct list_head *hook_list)
 {
@@ -3642,7 +3665,7 @@  static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 	if (flow)
 		nft_flow_rule_destroy(flow);
 err_release_rule:
-	nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE);
+	nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE_ERROR);
 	nf_tables_rule_destroy(&ctx, rule);
 err_release_expr:
 	for (i = 0; i < n; i++) {
@@ -4865,6 +4888,13 @@  void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set,
 			      enum nft_trans_phase phase)
 {
 	switch (phase) {
+	case NFT_TRANS_PREPARE_ERROR:
+		nft_set_trans_unbind(ctx, set);
+		if (nft_set_is_anonymous(set))
+			nft_deactivate_next(ctx->net, set);
+
+		set->use--;
+		break;
 	case NFT_TRANS_PREPARE:
 		if (nft_set_is_anonymous(set))
 			nft_deactivate_next(ctx->net, set);
@@ -7363,6 +7393,7 @@  void nf_tables_deactivate_flowtable(const struct nft_ctx *ctx,
 				    enum nft_trans_phase phase)
 {
 	switch (phase) {
+	case NFT_TRANS_PREPARE_ERROR:
 	case NFT_TRANS_PREPARE:
 	case NFT_TRANS_ABORT:
 	case NFT_TRANS_RELEASE:
diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c
index 457fc1e21841..900e75e8c346 100644
--- a/net/netfilter/nft_immediate.c
+++ b/net/netfilter/nft_immediate.c
@@ -150,6 +150,9 @@  static void nft_immediate_deactivate(const struct nft_ctx *ctx,
 				nft_rule_expr_deactivate(&chain_ctx, rule, phase);
 
 			switch (phase) {
+			case NFT_TRANS_PREPARE_ERROR:
+				nf_tables_unbind_chain(ctx, chain);
+				fallthrough;
 			case NFT_TRANS_PREPARE:
 				nft_deactivate_next(ctx->net, chain);
 				break;