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

Florian Westphal says:

====================
netfilter updates for net

Three late fixes for netfilter:

1) If nf_queue user requests packet truncation below size of l3 header,
   we corrupt the skb, then crash.  Reject such requests.

2) add cond_resched() calls when doing cycle detection in the
   nf_tables graph.  This avoids softlockup warning with certain
   rulesets.

3) Reject rulesets that use nftables 'queue' expression in family/chain
   combinations other than those that are supported.  Currently the ruleset
   will load, but when userspace attempts to reinject you get WARN splat +
   packet drops.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_queue: only allow supported familes and hooks
  netfilter: nf_tables: add rescheduling points during loop detection walks
  netfilter: nf_queue: do not allow packet truncation below transport header offset
====================

Link: https://lore.kernel.org/r/20220726192056.13497-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 39 insertions, 1 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 646d5fd53604..9f976b11d896 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3340,6 +3340,8 @@ int nft_chain_validate(const struct nft_ctx *ctx, const struct nft_chain *chain)
 			if (err < 0)
 				return err;
 		}
+
+		cond_resched();
 	}
 
 	return 0;
@@ -9367,9 +9369,13 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
 				break;
 			}
 		}
+
+		cond_resched();
 	}
 
 	list_for_each_entry(set, &ctx->table->sets, list) {
+		cond_resched();
+
 		if (!nft_is_active_next(ctx->net, set))
 			continue;
 		if (!(set->flags & NFT_SET_MAP) ||
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index a364f8e5e698..87a9009d5234 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -843,11 +843,16 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 }
 
 static int
-nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
+nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff)
 {
 	struct sk_buff *nskb;
 
 	if (diff < 0) {
+		unsigned int min_len = skb_transport_offset(e->skb);
+
+		if (data_len < min_len)
+			return -EINVAL;
+
 		if (pskb_trim(e->skb, data_len))
 			return -ENOMEM;
 	} else if (diff > 0) {
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,
 };