netfilter: nft_queue: only allow supported familes and hooks

Trying to use 'queue' statement in ingress (for example)
triggers a splat on reinject:

WARNING: CPU: 3 PID: 1345 at net/netfilter/nf_queue.c:291

... because nf_reinject cannot find the ruleset head.

The netdev family doesn't support async resume at the moment anyway,
so disallow loading such rulesets with a more appropriate
error message.

v2: add 'validate' callback and also check hook points, v1 did
allow ingress use in 'table inet', but that doesn't work either. (Pablo)

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_queue.c b/net/netfilter/nft_queue.c
index 15e4b7640dc00041dab7ddaebd26c20d26235753..da29e92c03e276e7a6a101fcd3b24eae1416ee37 100644 (file)
--- a/net/netfilter/nft_queue.c
+++ b/net/netfilter/nft_queue.c
@@ -68,6 +68,31 @@ static void nft_queue_sreg_eval(const struct nft_expr *expr,
        regs->verdict.code = ret;
 }
 
+static int nft_queue_validate(const struct nft_ctx *ctx,
+                             const struct nft_expr *expr,
+                             const struct nft_data **data)
+{
+       static const unsigned int supported_hooks = ((1 << NF_INET_PRE_ROUTING) |
+                                                    (1 << NF_INET_LOCAL_IN) |
+                                                    (1 << NF_INET_FORWARD) |
+                                                    (1 << NF_INET_LOCAL_OUT) |
+                                                    (1 << NF_INET_POST_ROUTING));
+
+       switch (ctx->family) {
+       case NFPROTO_IPV4:
+       case NFPROTO_IPV6:
+       case NFPROTO_INET:
+       case NFPROTO_BRIDGE:
+               break;
+       case NFPROTO_NETDEV: /* lacks okfn */
+               fallthrough;
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return nft_chain_validate_hooks(ctx->chain, supported_hooks);
+}
+
 static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = {
        [NFTA_QUEUE_NUM]        = { .type = NLA_U16 },
        [NFTA_QUEUE_TOTAL]      = { .type = NLA_U16 },
@@ -164,6 +189,7 @@ static const struct nft_expr_ops nft_queue_ops = {
        .eval           = nft_queue_eval,
        .init           = nft_queue_init,
        .dump           = nft_queue_dump,
+       .validate       = nft_queue_validate,
        .reduce         = NFT_REDUCE_READONLY,
 };
 
@@ -173,6 +199,7 @@ static const struct nft_expr_ops nft_queue_sreg_ops = {
        .eval           = nft_queue_sreg_eval,
        .init           = nft_queue_sreg_init,
        .dump           = nft_queue_sreg_dump,
+       .validate       = nft_queue_validate,
        .reduce         = NFT_REDUCE_READONLY,
 };