From 795231bc2490da4e0eb5caea1965b95590a254db Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 22 May 2017 17:47:56 +0100
Subject: [PATCH 1/2] netfilter: nft_set_hash: add nft_hash_buckets()
Patch-mainline: v4.13-rc1
Git-commit: 2111515abc46cb3e18b22d8551067029acfd1f55
References: CVE-2021-46992 bsc#1220638
Add nft_hash_buckets() helper function to calculate the number of
hashtable buckets based on the elements. This function can be reused
from the follow up patch to add non-resizable hashtables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/netfilter/nft_set_hash.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 3d3a6df4ce70..9edf7a1f5386 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -364,6 +364,11 @@ static void nft_hash_destroy(const struct nft_set *set)
(void *)set);
}
+static u32 nft_hash_buckets(u32 size)
+{
+ return roundup_pow_of_two(size * 4 / 3);
+}
+
static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
struct nft_set_estimate *est)
{
@@ -372,7 +377,7 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
esize = sizeof(struct nft_hash_elem);
if (desc->size) {
est->size = sizeof(struct nft_hash) +
- roundup_pow_of_two(desc->size * 4 / 3) *
+ nft_hash_buckets(desc->size) *
sizeof(struct nft_hash_elem *) +
desc->size * esize;
} else {
--
2.16.4