[PATCH 4.9 06/31] netfilter: nft_payload: report ERANGE for too long offset and length

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit 94254f990c07e9ddf1634e0b727fab821c3b5bf9 ]

Instead of offset and length are truncation to u8, report ERANGE.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nft_payload.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index f73d47b3ffb72..82bcd14fbcb3d 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -287,6 +287,7 @@ nft_payload_select_ops(const struct nft_ctx *ctx,
 {
 	enum nft_payload_bases base;
 	unsigned int offset, len;
+	int err;
 
 	if (tb[NFTA_PAYLOAD_BASE] == NULL ||
 	    tb[NFTA_PAYLOAD_OFFSET] == NULL ||
@@ -312,8 +313,13 @@ nft_payload_select_ops(const struct nft_ctx *ctx,
 	if (tb[NFTA_PAYLOAD_DREG] == NULL)
 		return ERR_PTR(-EINVAL);
 
-	offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
-	len    = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
+	err = nft_parse_u32_check(tb[NFTA_PAYLOAD_OFFSET], U8_MAX, &offset);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	err = nft_parse_u32_check(tb[NFTA_PAYLOAD_LEN], U8_MAX, &len);
+	if (err < 0)
+		return ERR_PTR(err);
 
 	if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
 	    base != NFT_PAYLOAD_LL_HEADER)
-- 
2.35.1