[PATCH 5.18 0186/1095] netfilter: nft_queue: only allow supported familes and hooks

Greg Kroah-Hartman
2022-08-15T20:32:45Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 47f4f510ad586032b85c89a0773fbb011d412425 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_queue.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/net/netfilter/nft_queue.c b/net/netfilter/nft_queue.c
index 15e4b7640dc0..da29e92c03e2 100644
--- 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,
};

--
2.35.1