5.15-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
[ 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@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 ac0979febdac..a355fbabe99f 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);