| From | Ben Hutchings <> | Date | Wed, 15 Feb 2017 22:41:40 +0000 | Subject | [PATCH 3.16 063/306] netfilter: nft_exthdr: Add size check on u8 nft_exthdr attributes |
| |
3.16.40-rc1 review patch. If anyone has any objections, please let me know.
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From: Laura Garcia Liebana <nevola@gmail.com>
commit 4da449ae1df9cfeb167e78f250b250eff64bc65e upstream.
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> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- net/netfilter/nft_exthdr.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -59,6 +59,7 @@ static int nft_exthdr_init(const struct { struct nft_exthdr *priv = nft_expr_priv(expr); int err; + u32 offset, len; if (tb[NFTA_EXTHDR_DREG] == NULL || tb[NFTA_EXTHDR_TYPE] == NULL || @@ -66,9 +67,15 @@ static int nft_exthdr_init(const struct tb[NFTA_EXTHDR_LEN] == NULL) return -EINVAL; + 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 -ERANGE; + 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])); + priv->offset = offset; + priv->len = len; if (priv->len == 0 || priv->len > FIELD_SIZEOF(struct nft_data, data)) return -EINVAL;
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