[PATCH net 0/2] Netfilter fixes for net

[PATCH net 0/2] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) nf_conntrack_tuple_taken() needs to recheck zone for
   NAT clash resolution, from Florian Westphal.

2) Restore support for stateful expressions when set definition
   specifies no stateful expressions.

Please, pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thanks!

----------------------------------------------------------------

The following changes since commit ce7536bc7398e2ae552d2fabb7e0e371a9f1fe46:

  vsock/virtio: update credit only if socket is not closed (2021-02-08 13:27:46 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to 664899e85c1312e51d2761e7f8b2f25d053e8489:

  netfilter: nftables: relax check for stateful expressions in set definition (2021-02-09 00:50:14 +0100)

----------------------------------------------------------------
Florian Westphal (1):
      netfilter: conntrack: skip identical origin tuple in same zone only

Pablo Neira Ayuso (1):
      netfilter: nftables: relax check for stateful expressions in set definition

 net/netfilter/nf_conntrack_core.c |  3 ++-
 net/netfilter/nf_tables_api.c     | 28 +++++++++++++++-------------
 2 files changed, 17 insertions(+), 14 deletions(-)

[PATCH net 1/2] netfilter: conntrack: skip identical origin tuple in same zone only

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

The origin skip check needs to re-test the zone. Else, we might skip
a colliding tuple in the reply direction.

This only occurs when using 'directional zones' where origin tuples
reside in different zones but the reply tuples share the same zone.

This causes the new conntrack entry to be dropped at confirmation time
because NAT clash resolution was elided.

Fixes: 4e35c1cb9460240 ("netfilter: nf_nat: skip nat clash resolution for same-origin entries")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 234b7cab37c3..ff0168736f6e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1229,7 +1229,8 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 			 * Let nf_ct_resolve_clash() deal with this later.
 			 */
 			if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-					      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple))
+					      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
+					      nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL))
 				continue;
 
 			NF_CT_STAT_INC_ATOMIC(net, found);
-- 
2.20.1

[PATCH net 2/2] netfilter: nftables: relax check for stateful expressions in set definition

[Pablo Neira Ayuso]

Restore the original behaviour where users are allowed to add an element
with any stateful expression if the set definition specifies no stateful
expressions. Make sure upper maximum number of stateful expressions of
NFT_SET_EXPR_MAX is not reached.

Fixes: 8cfd9b0f8515 ("netfilter: nftables: generalize set expressions support")
Fixes: 48b0ae046ee9 ("netfilter: nftables: netlink support for several set element expressions")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 43fe80f10313..8ee9f40cc0ea 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5281,6 +5281,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	struct nft_expr *expr_array[NFT_SET_EXPR_MAX] = {};
 	struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
 	u8 genmask = nft_genmask_next(ctx->net);
+	u32 flags = 0, size = 0, num_exprs = 0;
 	struct nft_set_ext_tmpl tmpl;
 	struct nft_set_ext *ext, *ext2;
 	struct nft_set_elem elem;
@@ -5290,7 +5291,6 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	struct nft_data_desc desc;
 	enum nft_registers dreg;
 	struct nft_trans *trans;
-	u32 flags = 0, size = 0;
 	u64 timeout;
 	u64 expiration;
 	int err, i;
@@ -5356,7 +5356,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (nla[NFTA_SET_ELEM_EXPR]) {
 		struct nft_expr *expr;
 
-		if (set->num_exprs != 1)
+		if (set->num_exprs && set->num_exprs != 1)
 			return -EOPNOTSUPP;
 
 		expr = nft_set_elem_expr_alloc(ctx, set,
@@ -5365,8 +5365,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			return PTR_ERR(expr);
 
 		expr_array[0] = expr;
+		num_exprs = 1;
 
-		if (set->exprs[0] && set->exprs[0]->ops != expr->ops) {
+		if (set->num_exprs && set->exprs[0]->ops != expr->ops) {
 			err = -EOPNOTSUPP;
 			goto err_set_elem_expr;
 		}
@@ -5375,12 +5376,10 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		struct nlattr *tmp;
 		int left;
 
-		if (set->num_exprs == 0)
-			return -EOPNOTSUPP;
-
 		i = 0;
 		nla_for_each_nested(tmp, nla[NFTA_SET_ELEM_EXPRESSIONS], left) {
-			if (i == set->num_exprs) {
+			if (i == NFT_SET_EXPR_MAX ||
+			    (set->num_exprs && set->num_exprs == i)) {
 				err = -E2BIG;
 				goto err_set_elem_expr;
 			}
@@ -5394,14 +5393,15 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 				goto err_set_elem_expr;
 			}
 			expr_array[i] = expr;
+			num_exprs++;
 
-			if (expr->ops != set->exprs[i]->ops) {
+			if (set->num_exprs && expr->ops != set->exprs[i]->ops) {
 				err = -EOPNOTSUPP;
 				goto err_set_elem_expr;
 			}
 			i++;
 		}
-		if (set->num_exprs != i) {
+		if (set->num_exprs && set->num_exprs != i) {
 			err = -EOPNOTSUPP;
 			goto err_set_elem_expr;
 		}
@@ -5409,6 +5409,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		err = nft_set_elem_expr_clone(ctx, set, expr_array);
 		if (err < 0)
 			goto err_set_elem_expr_clone;
+
+		num_exprs = set->num_exprs;
 	}
 
 	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
@@ -5433,8 +5435,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			nft_set_ext_add(&tmpl, NFT_SET_EXT_TIMEOUT);
 	}
 
-	if (set->num_exprs) {
-		for (i = 0; i < set->num_exprs; i++)
+	if (num_exprs) {
+		for (i = 0; i < num_exprs; i++)
 			size += expr_array[i]->ops->size;
 
 		nft_set_ext_add_length(&tmpl, NFT_SET_EXT_EXPRESSIONS,
@@ -5522,7 +5524,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		*nft_set_ext_obj(ext) = obj;
 		obj->use++;
 	}
-	for (i = 0; i < set->num_exprs; i++)
+	for (i = 0; i < num_exprs; i++)
 		nft_set_elem_expr_setup(ext, i, expr_array);
 
 	trans = nft_trans_elem_alloc(ctx, NFT_MSG_NEWSETELEM, set);
@@ -5584,7 +5586,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 err_parse_key:
 	nft_data_release(&elem.key.val, NFT_DATA_VALUE);
 err_set_elem_expr:
-	for (i = 0; i < set->num_exprs && expr_array[i]; i++)
+	for (i = 0; i < num_exprs && expr_array[i]; i++)
 		nft_expr_destroy(ctx, expr_array[i]);
 err_set_elem_expr_clone:
 	return err;
-- 
2.20.1

Re: [PATCH net 1/2] netfilter: conntrack: skip identical origin tuple in same zone only

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Tue,  9 Feb 2021 22:35:10 +0100 you wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> The origin skip check needs to re-test the zone. Else, we might skip
> a colliding tuple in the reply direction.
> 
> This only occurs when using 'directional zones' where origin tuples
> reside in different zones but the reply tuples share the same zone.
> 
> [...]

Here is the summary with links:
  - [net,1/2] netfilter: conntrack: skip identical origin tuple in same zone only
    https://git.kernel.org/netdev/net/c/07998281c268
  - [net,2/2] netfilter: nftables: relax check for stateful expressions in set definition
    https://git.kernel.org/netdev/net/c/664899e85c13

You are awesome, thank you!
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