From: Laura Garcia Liebana <nevola@gmail.com>
To: netfilter-devel@vger.kernel.org
Subject: [PATCH] netfilter: nf_tables: Add size check on u8 nft_exthdr attributes
Date: Tue, 9 Aug 2016 20:46:16 +0200 [thread overview]
Message-ID: <20160809184614.GA8947@sonyv> (raw)
Fix the direct assignment of offset and length attributes included in
nft_exthdr structure from u32 data to u8.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
---
net/netfilter/nft_exthdr.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
index ba7aed1..dec3c36 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -59,6 +59,7 @@ static int nft_exthdr_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_exthdr *priv = nft_expr_priv(expr);
+ u32 offset, len;
if (tb[NFTA_EXTHDR_DREG] == NULL ||
tb[NFTA_EXTHDR_TYPE] == NULL ||
@@ -67,8 +68,16 @@ static int nft_exthdr_init(const struct nft_ctx *ctx,
return -EINVAL;
priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
- priv->offset = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OFFSET]));
- priv->len = ntohl(nla_get_be32(tb[NFTA_EXTHDR_LEN]));
+
+ offset = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OFFSET]));
+ len = ntohl(nla_get_be32(tb[NFTA_EXTHDR_LEN]));
+
+ if (offset > U8_MAX || len > U8_MAX)
+ return -EINVAL;
+
+ priv->offset = offset;
+ priv->len = len;
+
priv->dreg = nft_parse_register(tb[NFTA_EXTHDR_DREG]);
return nft_validate_register_store(ctx, priv->dreg, NULL,
--
2.8.1
next reply other threads:[~2016-08-09 18:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-09 18:46 Laura Garcia Liebana [this message]
2016-08-10 10:57 ` [PATCH] netfilter: nf_tables: Add size check on u8 nft_exthdr attributes Pablo Neira Ayuso
2016-08-10 10:58 ` Pablo Neira Ayuso
2016-08-10 11:00 ` Laura Garcia
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