This patch introduces nft_set_pktinfo_unspec() that ensures proper
initialization all of pktinfo fields for non-IP traffic. This is used
by the bridge, netdev and arp families.
This new function relies on nft_set_pktinfo_proto_unspec() to set a new
tprot_set field that indicates if transport protocol information is
available. Remain fields are zeroed.
The meta expression has been also updated to check to tprot_set in first
place given that zero is a valid tprot value. Even a handcrafted packet
may come with the IPPROTO_RAW (255) protocol number so we can't rely on
this value as tprot unset.
Reported-by: Florian Westphal <f...@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
include/net/netfilter/nf_tables.h | 18 ++++++++++++++++++
include/net/netfilter/nf_tables_ipv4.h | 1 +
include/net/netfilter/nf_tables_ipv6.h | 1 +
net/bridge/netfilter/nf_tables_bridge.c | 6 +++---
net/ipv4/netfilter/nf_tables_arp.c | 2 +-
net/netfilter/nf_tables_netdev.c | 4 +++-
net/netfilter/nft_meta.c | 2 ++
7 files changed, 29 insertions(+), 5 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h
b/include/net/netfilter/nf_tables.h
index 8972468bc94b..a7a7cebc8d07 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -19,6 +19,7 @@ struct nft_pktinfo {
const struct net_device *out;
u8 pf;
u8 hook;
+ bool tprot_set;
u8 tprot;
/* for x_tables compatibility */
struct xt_action_param xt;
@@ -36,6 +37,23 @@ static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
pkt->pf = pkt->xt.family = state->pf;
}
+static inline void nft_set_pktinfo_proto_unspec(struct nft_pktinfo *pkt,
+ struct sk_buff *skb)
+{
+ pkt->tprot_set = false;
+ pkt->tprot = 0;
+ pkt->xt.thoff = 0;
+ pkt->xt.fragoff = 0;
+}
+
+static inline void nft_set_pktinfo_unspec(struct nft_pktinfo *pkt,
+ struct sk_buff *skb,
+ const struct nf_hook_state *state)
+{
+ nft_set_pktinfo(pkt, skb, state);
+ nft_set_pktinfo_proto_unspec(pkt, skb);
+}
+
/**
* struct nft_verdict - nf_tables verdict
*
diff --git a/include/net/netfilter/nf_tables_ipv4.h
b/include/net/netfilter/nf_tables_ipv4.h
index ca6ef6bf775e..af952f7843ee 100644
--- a/include/net/netfilter/nf_tables_ipv4.h
+++ b/include/net/netfilter/nf_tables_ipv4.h
@@ -14,6 +14,7 @@ nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
nft_set_pktinfo(pkt, skb, state);
ip = ip_hdr(pkt->skb);
+ pkt->tprot_set = true;
pkt->tprot = ip->protocol;
pkt->xt.thoff = ip_hdrlen(pkt->skb);
pkt->xt.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
diff --git a/include/net/netfilter/nf_tables_ipv6.h
b/include/net/netfilter/nf_tables_ipv6.h
index 8ad39a6a5fe1..6aeee47b1b5e 100644
--- a/include/net/netfilter/nf_tables_ipv6.h
+++ b/include/net/netfilter/nf_tables_ipv6.h
@@ -19,6 +19,7 @@ nft_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
if (protohdr < 0)
return -1;
+ pkt->tprot_set = true;
pkt->tprot = protohdr;
pkt->xt.thoff = thoff;
pkt->xt.fragoff = frag_off;
diff --git a/net/bridge/netfilter/nf_tables_bridge.c
b/net/bridge/netfilter/nf_tables_bridge.c
index a78c4e2826e5..29899887163e 100644
--- a/net/bridge/netfilter/nf_tables_bridge.c
+++ b/net/bridge/netfilter/nf_tables_bridge.c
@@ -71,7 +71,7 @@ static inline void nft_bridge_set_pktinfo_ipv4(struct
nft_pktinfo *pkt,
if (nft_bridge_iphdr_validate(skb))
nft_set_pktinfo_ipv4(pkt, skb, state);
else
- nft_set_pktinfo(pkt, skb, state);
+ nft_set_pktinfo_unspec(pkt, skb, state);
}
static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
@@ -83,7 +83,7 @@ static inline void nft_bridge_set_pktinfo_ipv6(struct
nft_pktinfo *pkt,
nft_set_pktinfo_ipv6(pkt, skb, state) == 0)
return;
#endif
- nft_set_pktinfo(pkt, skb, state);
+ nft_set_pktinfo_unspec(pkt, skb, state);
}
static unsigned int
@@ -101,7 +101,7 @@ nft_do_chain_bridge(void *priv,
nft_bridge_set_pktinfo_ipv6(&pkt, skb, state);
break;
default:
- nft_set_pktinfo(&pkt, skb, state);
+ nft_set_pktinfo_unspec(&pkt, skb, state);
break;
}
diff --git a/net/ipv4/netfilter/nf_tables_arp.c
b/net/ipv4/netfilter/nf_tables_arp.c
index cd84d4295a20..058c034be376 100644
--- a/net/ipv4/netfilter/nf_tables_arp.c
+++ b/net/ipv4/netfilter/nf_tables_arp.c
@@ -21,7 +21,7 @@ nft_do_chain_arp(void *priv,
{
struct nft_pktinfo pkt;
- nft_set_pktinfo(&pkt, skb, state);
+ nft_set_pktinfo_unspec(&pkt, skb, state);
return nft_do_chain(&pkt, priv);
}
diff --git a/net/netfilter/nf_tables_netdev.c b/net/netfilter/nf_tables_netdev.c
index 5eefe4a355c6..8de502b0c37b 100644
--- a/net/netfilter/nf_tables_netdev.c
+++ b/net/netfilter/nf_tables_netdev.c
@@ -41,6 +41,7 @@ nft_netdev_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
else if (len < thoff)
return;
+ pkt->tprot_set = true;
pkt->tprot = iph->protocol;
pkt->xt.thoff = thoff;
pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET;
@@ -74,6 +75,7 @@ __nft_netdev_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
if (protohdr < 0)
return;
+ pkt->tprot_set = true;
pkt->tprot = protohdr;
pkt->xt.thoff = thoff;
pkt->xt.fragoff = frag_off;
@@ -102,7 +104,7 @@ nft_do_chain_netdev(void *priv, struct sk_buff *skb,
nft_netdev_set_pktinfo_ipv6(&pkt, skb, state);
break;
default:
- nft_set_pktinfo(&pkt, skb, state);
+ nft_set_pktinfo_unspec(&pkt, skb, state);
break;
}
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 2863f3493038..14264edf2d77 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -52,6 +52,8 @@ void nft_meta_get_eval(const struct nft_expr *expr,
*dest = pkt->pf;
break;
case NFT_META_L4PROTO:
+ if (!pkt->tprot_set)
+ goto err;
*dest = pkt->tprot;
break;
case NFT_META_PRIORITY:
--
2.1.4
