[PATCH net 0/5] Netfilter fixes for net

[PATCH net 0/5] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) Incorrect helper module alias in netbios_ns, from Florian Westphal.

2) Remove unused variable in nf_tables.

3) Uninitialized last expression in nf_tables register tracking.

4) Memleak in nft_connlimit after moving stateful data out of the
   expression data area.

5) Bogus invalid stats update when NF_REPEAT is returned, from Florian.

Please, pull these changes from:

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

Thanks.

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

The following changes since commit 7d6019b602de660bfc6a542a68630006ace83b90:

  Revert "net: vertexcom: default to disabled on kbuild" (2022-01-10 21:11:07 -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 830af2eba40327abec64325a5b08b1e85c37a2e0:

  netfilter: conntrack: don't increment invalid counter on NF_REPEAT (2022-01-16 00:55:27 +0100)

----------------------------------------------------------------
Florian Westphal (2):
      netfilter: nf_conntrack_netbios_ns: fix helper module alias
      netfilter: conntrack: don't increment invalid counter on NF_REPEAT

Pablo Neira Ayuso (3):
      netfilter: nf_tables: remove unused variable
      netfilter: nf_tables: set last expression in register tracking area
      netfilter: nft_connlimit: memleak if nf_ct_netns_get() fails

 net/netfilter/nf_conntrack_core.c       |  8 +++++---
 net/netfilter/nf_conntrack_netbios_ns.c |  5 +++--
 net/netfilter/nf_tables_api.c           |  4 +---
 net/netfilter/nft_connlimit.c           | 11 ++++++++++-
 4 files changed, 19 insertions(+), 9 deletions(-)

[PATCH net 1/5] netfilter: nf_conntrack_netbios_ns: fix helper module alias

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

The helper gets registered as 'netbios-ns', not netbios_ns.
Intentionally not adding a fixes-tag because i don't want this to go to
stable. This wasn't noticed for a very long time so no so no need to risk
regressions.

Reported-by: Yi Chen <yiche@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_netbios_ns.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_netbios_ns.c b/net/netfilter/nf_conntrack_netbios_ns.c
index 7f19ee259609..55415f011943 100644
--- a/net/netfilter/nf_conntrack_netbios_ns.c
+++ b/net/netfilter/nf_conntrack_netbios_ns.c
@@ -20,13 +20,14 @@
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_expect.h>
 
+#define HELPER_NAME	"netbios-ns"
 #define NMBD_PORT	137
 
 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("ip_conntrack_netbios_ns");
-MODULE_ALIAS_NFCT_HELPER("netbios_ns");
+MODULE_ALIAS_NFCT_HELPER(HELPER_NAME);
 
 static unsigned int timeout __read_mostly = 3;
 module_param(timeout, uint, 0400);
@@ -44,7 +45,7 @@ static int netbios_ns_help(struct sk_buff *skb, unsigned int protoff,
 }
 
 static struct nf_conntrack_helper helper __read_mostly = {
-	.name			= "netbios-ns",
+	.name			= HELPER_NAME,
 	.tuple.src.l3num	= NFPROTO_IPV4,
 	.tuple.src.u.udp.port	= cpu_to_be16(NMBD_PORT),
 	.tuple.dst.protonum	= IPPROTO_UDP,
-- 
2.30.2

[PATCH net 2/5] netfilter: nf_tables: remove unused variable

[Pablo Neira Ayuso]

> Remove unused variable and fix missing initialization.
>
> >> net/netfilter/nf_tables_api.c:8266:6: warning: variable 'i' set but not used [-Wunused-but-set-variable]
>            int i;
>                ^

Fixes: 2c865a8a28a1 ("netfilter: nf_tables: add rule blob layout")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 77938b1042f3..1cde8cd0d1a7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -8264,14 +8264,12 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 	void *data, *data_boundary;
 	struct nft_rule_dp *prule;
 	struct nft_rule *rule;
-	int i;
 
 	/* already handled or inactive chain? */
 	if (chain->blob_next || !nft_is_active_next(net, chain))
 		return 0;
 
 	rule = list_entry(&chain->rules, struct nft_rule, list);
-	i = 0;
 
 	data_size = 0;
 	list_for_each_entry_continue(rule, &chain->rules, list) {
-- 
2.30.2

[PATCH net 3/5] netfilter: nf_tables: set last expression in register tracking area

[Pablo Neira Ayuso]

nft_rule_for_each_expr() sets on last to nft_rule_last(), however, this
is coming after track.last field is set on.

Use nft_expr_last() to set track.last accordingly.

Fixes: 12e4ecfa244b ("netfilter: nf_tables: add register tracking infrastructure")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 1cde8cd0d1a7..cf454f8ca2b0 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -8299,7 +8299,7 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 			return -ENOMEM;
 
 		size = 0;
-		track.last = last;
+		track.last = nft_expr_last(rule);
 		nft_rule_for_each_expr(expr, last, rule) {
 			track.cur = expr;
 
-- 
2.30.2

[PATCH net 4/5] netfilter: nft_connlimit: memleak if nf_ct_netns_get() fails

[Pablo Neira Ayuso]

Check if nf_ct_netns_get() fails then release the limit object
previously allocated via kmalloc().

Fixes: 37f319f37d90 ("netfilter: nft_connlimit: move stateful fields out of expression data")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_connlimit.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_connlimit.c b/net/netfilter/nft_connlimit.c
index 7d00a1452b1d..3362417ebfdb 100644
--- a/net/netfilter/nft_connlimit.c
+++ b/net/netfilter/nft_connlimit.c
@@ -62,6 +62,7 @@ static int nft_connlimit_do_init(const struct nft_ctx *ctx,
 {
 	bool invert = false;
 	u32 flags, limit;
+	int err;
 
 	if (!tb[NFTA_CONNLIMIT_COUNT])
 		return -EINVAL;
@@ -84,7 +85,15 @@ static int nft_connlimit_do_init(const struct nft_ctx *ctx,
 	priv->limit	= limit;
 	priv->invert	= invert;
 
-	return nf_ct_netns_get(ctx->net, ctx->family);
+	err = nf_ct_netns_get(ctx->net, ctx->family);
+	if (err < 0)
+		goto err_netns;
+
+	return 0;
+err_netns:
+	kfree(priv->list);
+
+	return err;
 }
 
 static void nft_connlimit_do_destroy(const struct nft_ctx *ctx,
-- 
2.30.2

[PATCH net 5/5] netfilter: conntrack: don't increment invalid counter on NF_REPEAT

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

The packet isn't invalid, REPEAT means we're trying again after cleaning
out a stale connection, e.g. via tcp tracker.

This caused increases of invalid stat counter in a test case involving
frequent connection reuse, even though no packet is actually invalid.

Fixes: 56a62e2218f5 ("netfilter: conntrack: fix NF_REPEAT handling")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 894a325d39f2..d6aa5b47031e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1924,15 +1924,17 @@ nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
 		pr_debug("nf_conntrack_in: Can't track with proto module\n");
 		nf_ct_put(ct);
 		skb->_nfct = 0;
-		NF_CT_STAT_INC_ATOMIC(state->net, invalid);
-		if (ret == -NF_DROP)
-			NF_CT_STAT_INC_ATOMIC(state->net, drop);
 		/* Special case: TCP tracker reports an attempt to reopen a
 		 * closed/aborted connection. We have to go back and create a
 		 * fresh conntrack.
 		 */
 		if (ret == -NF_REPEAT)
 			goto repeat;
+
+		NF_CT_STAT_INC_ATOMIC(state->net, invalid);
+		if (ret == -NF_DROP)
+			NF_CT_STAT_INC_ATOMIC(state->net, drop);
+
 		ret = -ret;
 		goto out;
 	}
-- 
2.30.2

Re: [PATCH net 1/5] netfilter: nf_conntrack_netbios_ns: fix helper module alias

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by Pablo Neira Ayuso <pablo@netfilter.org>:

On Thu, 20 Jan 2022 13:52:08 +0100 you wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> The helper gets registered as 'netbios-ns', not netbios_ns.
> Intentionally not adding a fixes-tag because i don't want this to go to
> stable. This wasn't noticed for a very long time so no so no need to risk
> regressions.
> 
> [...]

Here is the summary with links:
  - [net,1/5] netfilter: nf_conntrack_netbios_ns: fix helper module alias
    https://git.kernel.org/netdev/net/c/0e906607b9c5
  - [net,2/5] netfilter: nf_tables: remove unused variable
    https://git.kernel.org/netdev/net/c/cf46eacbc156
  - [net,3/5] netfilter: nf_tables: set last expression in register tracking area
    https://git.kernel.org/netdev/net/c/fe75e84a8fe1
  - [net,4/5] netfilter: nft_connlimit: memleak if nf_ct_netns_get() fails
    https://git.kernel.org/netdev/net/c/7d70984a1ad4
  - [net,5/5] netfilter: conntrack: don't increment invalid counter on NF_REPEAT
    https://git.kernel.org/netdev/net/c/830af2eba403

You are awesome, thank you!
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