The cgroup matching logic in nft_meta currently bails out early
if skb->sk == NULL, ie, when the check is run on a socket that has
not yet been looked up by early demux.
To fix this, use the socket lookup helpers to determine the receiver
socket in such cases.
Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Alexey Perevalov <a.perevalov@xxxxxxxxxxx>
Cc: Florian Westphal <fw@xxxxxxxxx>
---
net/netfilter/Kconfig | 2 ++
net/netfilter/nft_meta.c | 35 ++++++++++++++++++++++++++++++++---
2 files changed, 34 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 11c7e37..2d3294c 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -475,6 +475,8 @@ config NFT_EXTHDR
config NFT_META
tristate "Netfilter nf_tables meta module"
+ select NF_SOCK_IPV4
+ select NF_SOCK_IPV6 if IP6_NF_IPTABLES
help
This option adds the "meta" expression that you can use to match and
to set packet metainformation such as the packet mark.
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 52561e1..ecc3de8 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -13,6 +13,8 @@
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/in.h>
#include <linux/ip.h>
@@ -166,11 +168,38 @@ void nft_meta_get_eval(const struct nft_expr *expr,
goto err;
*dest = out->group;
break;
- case NFT_META_CGROUP:
- if (skb->sk == NULL || !sk_fullsock(skb->sk))
+ case NFT_META_CGROUP: {
+ struct sock *sk;
+
+ if (skb->sk && sk_fullsock(skb->sk)) {
+ *dest = skb->sk->sk_classid;
+ break;
+ }
+
+ if (!in)
goto err;
- *dest = skb->sk->sk_classid;
+
+ switch (pkt->ops->pf) {
+ case NFPROTO_IPV4:
+ sk = nf_socket_lookup_v4(skb, in);
+ break;
+ case NFPROTO_IPV6:
+ sk = nf_socket_lookup_v6(skb, in);
+ break;
+ default:
+ goto err;
+ }
+
+ if (!sk)
+ goto err;
+
+ *dest = sk->sk_classid;
+
+ if (!sk_fullsock(sk))
+ sock_gen_put(sk);
+
break;
+ }
default:
WARN_ON(1);
goto err;
--
2.4.0
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