6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[ Upstream commit 91a139cee1202a4599a380810d93c69b5bac6197 ]
Bail out if userspace provides unsupported flags, otherwise future
extensions to the limit expression will be silently ignored by the
kernel.
Fixes: c7862a5f0de5 ("netfilter: nft_limit: allow to invert matching criteria")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netfilter/nft_limit.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
index 981addb2d051..75c05ef885a9 100644
--- a/net/netfilter/nft_limit.c
+++ b/net/netfilter/nft_limit.c
@@ -58,6 +58,7 @@ static inline bool nft_limit_eval(struct nft_limit_priv *priv, u64 cost)
static int nft_limit_init(struct nft_limit_priv *priv,
const struct nlattr * const tb[], bool pkts)
{
+ bool invert = false;
u64 unit, tokens;
if (tb[NFTA_LIMIT_RATE] == NULL ||
@@ -90,19 +91,23 @@ static int nft_limit_init(struct nft_limit_priv *priv,
priv->rate);
}
+ if (tb[NFTA_LIMIT_FLAGS]) {
+ u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));
+
+ if (flags & ~NFT_LIMIT_F_INV)
+ return -EOPNOTSUPP;
+
+ if (flags & NFT_LIMIT_F_INV)
+ invert = true;
+ }
+
priv->limit = kmalloc(sizeof(*priv->limit), GFP_KERNEL_ACCOUNT);
if (!priv->limit)
return -ENOMEM;
priv->limit->tokens = tokens;
priv->tokens_max = priv->limit->tokens;
-
- if (tb[NFTA_LIMIT_FLAGS]) {
- u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));
-
- if (flags & NFT_LIMIT_F_INV)
- priv->invert = true;
- }
+ priv->invert = invert;
priv->limit->last = ktime_get_ns();
spin_lock_init(&priv->limit->lock);
--
2.43.0
