[PATCH net 0/3] Netfilter fixes for net

[PATCH net 0/3] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) Fix PPPoE and QinQ with flowtable inet family.

2) Missing register validation in nf_tables.

3) Initialize registers to avoid stack memleak to userspace.

Please, pull these changes from:

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

Thanks.

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

The following changes since commit dea2d93a8ba437460c5f21bdfa4ada57fa1d2179:

  Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue (2022-03-16 10:07:43 +0000)

are available in the Git repository at:

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

for you to fetch changes up to 4c905f6740a365464e91467aa50916555b28213d:

  netfilter: nf_tables: initialize registers in nft_do_chain() (2022-03-17 15:50:27 +0100)

----------------------------------------------------------------
Pablo Neira Ayuso (3):
      netfilter: flowtable: Fix QinQ and pppoe support for inet table
      netfilter: nf_tables: validate registers coming from userspace.
      netfilter: nf_tables: initialize registers in nft_do_chain()

 include/net/netfilter/nf_flow_table.h | 18 ++++++++++++++++++
 net/netfilter/nf_flow_table_inet.c    | 17 +++++++++++++++++
 net/netfilter/nf_flow_table_ip.c      | 18 ------------------
 net/netfilter/nf_tables_api.c         | 22 +++++++++++++++++-----
 net/netfilter/nf_tables_core.c        |  2 +-
 5 files changed, 53 insertions(+), 24 deletions(-)

[PATCH net 1/3] netfilter: flowtable: Fix QinQ and pppoe support for inet table

[Pablo Neira Ayuso]

nf_flow_offload_inet_hook() does not check for 802.1q and PPPoE.
Fetch inner ethertype from these encapsulation protocols.

Fixes: 72efd585f714 ("netfilter: flowtable: add pppoe support")
Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_flow_table.h | 18 ++++++++++++++++++
 net/netfilter/nf_flow_table_inet.c    | 17 +++++++++++++++++
 net/netfilter/nf_flow_table_ip.c      | 18 ------------------
 3 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index bd59e950f4d6..64daafd1fc41 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -10,6 +10,8 @@
 #include <linux/netfilter/nf_conntrack_tuple_common.h>
 #include <net/flow_offload.h>
 #include <net/dst.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_defs.h>
 
 struct nf_flowtable;
 struct nf_flow_rule;
@@ -317,4 +319,20 @@ int nf_flow_rule_route_ipv6(struct net *net, const struct flow_offload *flow,
 int nf_flow_table_offload_init(void);
 void nf_flow_table_offload_exit(void);
 
+static inline __be16 nf_flow_pppoe_proto(const struct sk_buff *skb)
+{
+	__be16 proto;
+
+	proto = *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
+			     sizeof(struct pppoe_hdr)));
+	switch (proto) {
+	case htons(PPP_IP):
+		return htons(ETH_P_IP);
+	case htons(PPP_IPV6):
+		return htons(ETH_P_IPV6);
+	}
+
+	return 0;
+}
+
 #endif /* _NF_FLOW_TABLE_H */
diff --git a/net/netfilter/nf_flow_table_inet.c b/net/netfilter/nf_flow_table_inet.c
index 5c57ade6bd05..0ccabf3fa6aa 100644
--- a/net/netfilter/nf_flow_table_inet.c
+++ b/net/netfilter/nf_flow_table_inet.c
@@ -6,12 +6,29 @@
 #include <linux/rhashtable.h>
 #include <net/netfilter/nf_flow_table.h>
 #include <net/netfilter/nf_tables.h>
+#include <linux/if_vlan.h>
 
 static unsigned int
 nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb,
 			  const struct nf_hook_state *state)
 {
+	struct vlan_ethhdr *veth;
+	__be16 proto;
+
 	switch (skb->protocol) {
+	case htons(ETH_P_8021Q):
+		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
+		proto = veth->h_vlan_encapsulated_proto;
+		break;
+	case htons(ETH_P_PPP_SES):
+		proto = nf_flow_pppoe_proto(skb);
+		break;
+	default:
+		proto = skb->protocol;
+		break;
+	}
+
+	switch (proto) {
 	case htons(ETH_P_IP):
 		return nf_flow_offload_ip_hook(priv, skb, state);
 	case htons(ETH_P_IPV6):
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 889cf88d3dba..6257d87c3a56 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -8,8 +8,6 @@
 #include <linux/ipv6.h>
 #include <linux/netdevice.h>
 #include <linux/if_ether.h>
-#include <linux/if_pppox.h>
-#include <linux/ppp_defs.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
@@ -239,22 +237,6 @@ static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
 	return NF_STOLEN;
 }
 
-static inline __be16 nf_flow_pppoe_proto(const struct sk_buff *skb)
-{
-	__be16 proto;
-
-	proto = *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
-			     sizeof(struct pppoe_hdr)));
-	switch (proto) {
-	case htons(PPP_IP):
-		return htons(ETH_P_IP);
-	case htons(PPP_IPV6):
-		return htons(ETH_P_IPV6);
-	}
-
-	return 0;
-}
-
 static bool nf_flow_skb_encap_protocol(const struct sk_buff *skb, __be16 proto,
 				       u32 *offset)
 {
-- 
2.30.2

[PATCH net 2/3] netfilter: nf_tables: validate registers coming from userspace.

[Pablo Neira Ayuso]

Bail out in case userspace uses unsupported registers.

Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d71a33ae39b3..1f5a0eece0d1 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9275,17 +9275,23 @@ int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest)
 }
 EXPORT_SYMBOL_GPL(nft_parse_u32_check);
 
-static unsigned int nft_parse_register(const struct nlattr *attr)
+static unsigned int nft_parse_register(const struct nlattr *attr, u32 *preg)
 {
 	unsigned int reg;
 
 	reg = ntohl(nla_get_be32(attr));
 	switch (reg) {
 	case NFT_REG_VERDICT...NFT_REG_4:
-		return reg * NFT_REG_SIZE / NFT_REG32_SIZE;
+		*preg = reg * NFT_REG_SIZE / NFT_REG32_SIZE;
+		break;
+	case NFT_REG32_00...NFT_REG32_15:
+		*preg = reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00;
+		break;
 	default:
-		return reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00;
+		return -ERANGE;
 	}
+
+	return 0;
 }
 
 /**
@@ -9327,7 +9333,10 @@ int nft_parse_register_load(const struct nlattr *attr, u8 *sreg, u32 len)
 	u32 reg;
 	int err;
 
-	reg = nft_parse_register(attr);
+	err = nft_parse_register(attr, &reg);
+	if (err < 0)
+		return err;
+
 	err = nft_validate_register_load(reg, len);
 	if (err < 0)
 		return err;
@@ -9382,7 +9391,10 @@ int nft_parse_register_store(const struct nft_ctx *ctx,
 	int err;
 	u32 reg;
 
-	reg = nft_parse_register(attr);
+	err = nft_parse_register(attr, &reg);
+	if (err < 0)
+		return err;
+
 	err = nft_validate_register_store(ctx, reg, data, type, len);
 	if (err < 0)
 		return err;
-- 
2.30.2

[PATCH net 3/3] netfilter: nf_tables: initialize registers in nft_do_chain()

[Pablo Neira Ayuso]

Initialize registers to avoid stack leak into userspace.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 36e73f9828c5..8af98239655d 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -201,7 +201,7 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv)
 	const struct nft_rule_dp *rule, *last_rule;
 	const struct net *net = nft_net(pkt);
 	const struct nft_expr *expr, *last;
-	struct nft_regs regs;
+	struct nft_regs regs = {};
 	unsigned int stackptr = 0;
 	struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
 	bool genbit = READ_ONCE(net->nft.gencursor);
-- 
2.30.2

Re: [PATCH net 1/3] netfilter: flowtable: Fix QinQ and pppoe support for inet table

[patchwork-bot+netdevbpf]

Hello:

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

On Thu, 17 Mar 2022 21:25:32 +0100 you wrote:
> nf_flow_offload_inet_hook() does not check for 802.1q and PPPoE.
> Fetch inner ethertype from these encapsulation protocols.
> 
> Fixes: 72efd585f714 ("netfilter: flowtable: add pppoe support")
> Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> [...]

Here is the summary with links:
  - [net,1/3] netfilter: flowtable: Fix QinQ and pppoe support for inet table
    https://git.kernel.org/netdev/net/c/0492d857636e
  - [net,2/3] netfilter: nf_tables: validate registers coming from userspace.
    https://git.kernel.org/netdev/net/c/6e1acfa387b9
  - [net,3/3] netfilter: nf_tables: initialize registers in nft_do_chain()
    https://git.kernel.org/netdev/net/c/4c905f6740a3

You are awesome, thank you!
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