Use nft_parse_u32_check() to make sure we don't get a value over the
unsigned 8-bit integer. Moreover, make sure this value doesn't go over
the two supported range comparison modes.
Fixes: 9286c2eb1fda ("netfilter: nft_range: validate operation netlink attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nft_range.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nft_range.c b/net/netfilter/nft_range.c
index c6d5358482d1..9bc4586c3006 100644
--- a/net/netfilter/nft_range.c
+++ b/net/netfilter/nft_range.c
@@ -59,6 +59,7 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
struct nft_range_expr *priv = nft_expr_priv(expr);
struct nft_data_desc desc_from, desc_to;
int err;
+ u32 op;
err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
&desc_from, tb[NFTA_RANGE_FROM_DATA]);
@@ -80,7 +81,20 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
if (err < 0)
goto err2;
- priv->op = ntohl(nla_get_be32(tb[NFTA_RANGE_OP]));
+ err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op);
+ if (err < 0)
+ goto err2;
+
+ switch (op) {
+ case NFT_RANGE_EQ:
+ case NFT_RANGE_NEQ:
+ break;
+ default:
+ err = -EINVAL;
+ goto err2;
+ }
+
+ priv->op = op;
priv->len = desc_from.len;
return 0;
err2:
--
2.1.4
--
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