[PATCH nft 1/2] netlink_delinearize: release expressions in context registers

[PATCH nft 1/2] netlink_delinearize: release expressions in context registers

[Pablo Neira Ayuso]

netlink_release_registers() needs to go a bit further to release the
expressions in the register array. This should be safe since
netlink_get_register() clones expressions in the context registers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/netlink.h         | 4 +++-
 src/netlink_delinearize.c | 6 +++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/netlink.h b/include/netlink.h
index a20ebbe4740c..0c08b1abbf6a 100644
--- a/include/netlink.h
+++ b/include/netlink.h
@@ -14,12 +14,14 @@
 
 #include <rule.h>
 
+#define MAX_REGS	(1 + NFT_REG32_15 - NFT_REG32_00)
+
 struct netlink_parse_ctx {
 	struct list_head	*msgs;
 	struct table		*table;
 	struct rule		*rule;
 	struct stmt		*stmt;
-	struct expr		*registers[1 + NFT_REG32_15 - NFT_REG32_00 + 1];
+	struct expr		*registers[MAX_REGS + 1];
 	unsigned int		debug_mask;
 };
 
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index c018e78b0292..a1c775e679e4 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -63,7 +63,7 @@ static void netlink_set_register(struct netlink_parse_ctx *ctx,
 				 enum nft_registers reg,
 				 struct expr *expr)
 {
-	if (reg == NFT_REG_VERDICT || reg > 1 + NFT_REG32_15 - NFT_REG32_00) {
+	if (reg == NFT_REG_VERDICT || reg > MAX_REGS) {
 		netlink_error(ctx, &expr->location,
 			      "Invalid destination register %u", reg);
 		expr_free(expr);
@@ -82,7 +82,7 @@ static struct expr *netlink_get_register(struct netlink_parse_ctx *ctx,
 {
 	struct expr *expr;
 
-	if (reg == NFT_REG_VERDICT || reg > 1 + NFT_REG32_15 - NFT_REG32_00) {
+	if (reg == NFT_REG_VERDICT || reg > MAX_REGS) {
 		netlink_error(ctx, loc, "Invalid source register %u", reg);
 		return NULL;
 	}
@@ -98,7 +98,7 @@ static void netlink_release_registers(struct netlink_parse_ctx *ctx)
 {
 	int i;
 
-	for (i = 0; i <= NFT_REG_MAX; i++)
+	for (i = 0; i < MAX_REGS; i++)
 		expr_free(ctx->registers[i]);
 }
 
-- 
2.11.0

[PATCH nft 2/2] netlink_delinearize: release expression before calling netlink_parse_concat_expr()

[Pablo Neira Ayuso]

netlink_get_register() clones the expression in the register. Release
this expression before calling netlink_parse_concat_expr() to
deconstruct the concatenation.

==15069==    at 0x4C2BBAF: malloc (vg_replace_malloc.c:299)
==15069==    by 0x4E79508: xmalloc (utils.c:36)
==15069==    by 0x4E795ED: xzalloc (utils.c:65)
==15069==    by 0x4E6029B: dtype_alloc (datatype.c:1073)
==15069==    by 0x4E6029B: concat_type_alloc (datatype.c:1127)
==15069==    by 0x4E6D3B3: netlink_delinearize_set (netlink.c:578)
==15069==    by 0x4E6D68E: list_set_cb (netlink.c:648)
==15069==    by 0x5F34023: nftnl_set_list_foreach (set.c:780)
==15069==    by 0x4E6D6F3: netlink_list_sets (netlink.c:669)
==15069==    by 0x4E5A7A3: cache_init_objects (rule.c:159)
==15069==    by 0x4E5A7A3: cache_init (rule.c:216)
==15069==    by 0x4E5A7A3: cache_update (rule.c:266)
==15069==    by 0x4E7E09E: nft_evaluate (libnftables.c:388)
==15069==    by 0x4E7E85B: nft_run_cmd_from_buffer (libnftables.c:428)

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/netlink_delinearize.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index a1c775e679e4..0270e1fd7067 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -293,6 +293,7 @@ static void netlink_parse_cmp(struct netlink_parse_ctx *ctx,
 	    expr_basetype(left) != &string_type) {
 		return netlink_error(ctx, loc, "Relational expression size mismatch");
 	} else if (left->len > 0 && left->len < right->len) {
+		expr_free(left);
 		left = netlink_parse_concat_expr(ctx, loc, sreg, right->len);
 		if (left == NULL)
 			return;
@@ -329,6 +330,7 @@ static void netlink_parse_lookup(struct netlink_parse_ctx *ctx,
 				     "Lookup expression has no left hand side");
 
 	if (left->len < set->key->len) {
+		expr_free(left);
 		left = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 		if (left == NULL)
 			return;
@@ -1317,6 +1319,7 @@ static void netlink_parse_dynset(struct netlink_parse_ctx *ctx,
 				     "Dynset statement has no key expression");
 
 	if (expr->len < set->key->len) {
+		expr_free(expr);
 		expr = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 		if (expr == NULL)
 			return;
@@ -1408,6 +1411,7 @@ static void netlink_parse_objref(struct netlink_parse_ctx *ctx,
 					     "objref expression has no left hand side");
 
 		if (left->len < set->key->len) {
+			expr_free(left);
 			left = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 			if (left == NULL)
 				return;
-- 
2.11.0