netfilter: nf_tables: allow large allocations for new sets

The new fixed size hashtable backend implementation may result in a
large array of buckets that would spew splats from mm. Update this code
to fall back on vmalloc in case the memory allocation order is too
costly.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -13,6 +13,7 @@
 #include <linux/list.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
+#include <linux/vmalloc.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nfnetlink.h>
 #include <linux/netfilter/nf_tables.h>
@@ -3054,10 +3055,11 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	if (ops->privsize != NULL)
 		size = ops->privsize(nla, &desc);
 
-	err = -ENOMEM;
-	set = kzalloc(sizeof(*set) + size + udlen, GFP_KERNEL);
-	if (set == NULL)
+	set = kvzalloc(sizeof(*set) + size + udlen, GFP_KERNEL);
+	if (!set) {
+		err = -ENOMEM;
 		goto err1;
+	}
 
 	nla_strlcpy(name, nla[NFTA_SET_NAME], sizeof(set->name));
 	err = nf_tables_set_alloc_name(&ctx, set, name);
@@ -3100,7 +3102,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 err3:
 	ops->destroy(set);
 err2:
-	kfree(set);
+	kvfree(set);
 err1:
 	module_put(ops->type->owner);
 	return err;
@@ -3110,7 +3112,7 @@ static void nft_set_destroy(struct nft_set *set)
 {
 	set->ops->destroy(set);
 	module_put(set->ops->type->owner);
-	kfree(set);
+	kvfree(set);
 }
 
 static void nf_tables_set_destroy(const struct nft_ctx *ctx, struct nft_set *set)