[PATCH 3.16 137/306] netfilter: nf_tables: underflow in nft_parse_u32_check()

[Ben Hutchings]

3.16.40-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 09525a09ad3099efd9ba49b0b90bddc350d6b53a upstream.

We don't want to allow negatives here.

Fixes: 36b701fae12a ('netfilter: nf_tables: validate maximum value of u32 netlink attributes')
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3725,7 +3725,7 @@ static int nf_tables_check_loops(const s
  */
 unsigned int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest)
 {
-	int val;
+	u32 val;
 
 	val = ntohl(nla_get_be32(attr));
 	if (val > max)