diff mbox

[04/11] netfilter: nft_hash: validate maximum value of u32 netlink hash attribute

Message ID 1480543045-3389-5-git-send-email-pablo@netfilter.org
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Pablo Neira Ayuso Nov. 30, 2016, 9:57 p.m. UTC 
From: Laura Garcia Liebana <nevola@gmail.com>

Use the function nft_parse_u32_check() to fetch the value and validate
the u32 attribute into the hash len u8 field.

This patch revisits 4da449ae1df9 ("netfilter: nft_exthdr: Add size check
on u8 nft_exthdr attributes").

Fixes: cb1b69b0b15b ("netfilter: nf_tables: add hash expression")
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_hash.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index baf694de3935..d5447a22275c 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -53,6 +53,7 @@  static int nft_hash_init(const struct nft_ctx *ctx,
 {
 	struct nft_hash *priv = nft_expr_priv(expr);
 	u32 len;
+	int err;
 
 	if (!tb[NFTA_HASH_SREG] ||
 	    !tb[NFTA_HASH_DREG] ||
@@ -67,8 +68,10 @@  static int nft_hash_init(const struct nft_ctx *ctx,
 	priv->sreg = nft_parse_register(tb[NFTA_HASH_SREG]);
 	priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
 
-	len = ntohl(nla_get_be32(tb[NFTA_HASH_LEN]));
-	if (len == 0 || len > U8_MAX)
+	err = nft_parse_u32_check(tb[NFTA_HASH_LEN], U8_MAX, &len);
+	if (err < 0)
+		return err;
+	if (len == 0)
 		return -ERANGE;
 
 	priv->len = len;