[PATCH 5.4 23/77] netfilter: nft_payload: do not truncate csum_offset and csum_type

Greg Kroah-Hartman
2022-09-02T12:36:05Z

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

[ Upstream commit 7044ab281febae9e2fa9b0b247693d6026166293 ]

Instead report ERANGE if csum_offset is too long, and EOPNOTSUPP if type
is not support.

Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_payload.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 7520ec17cabb7..6ed6ccef5e1ad 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -558,6 +558,8 @@ static int nft_payload_set_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_payload_set *priv = nft_expr_priv(expr);
+ u32 csum_offset, csum_type = NFT_PAYLOAD_CSUM_NONE;
+ int err;

priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
@@ -565,11 +567,15 @@ static int nft_payload_set_init(const struct nft_ctx *ctx,
priv->sreg = nft_parse_register(tb[NFTA_PAYLOAD_SREG]);

if (tb[NFTA_PAYLOAD_CSUM_TYPE])
- priv->csum_type =
- ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE]));
- if (tb[NFTA_PAYLOAD_CSUM_OFFSET])
- priv->csum_offset =
- ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET]));
+ csum_type = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE]));
+ if (tb[NFTA_PAYLOAD_CSUM_OFFSET]) {
+ err = nft_parse_u32_check(tb[NFTA_PAYLOAD_CSUM_OFFSET], U8_MAX,
+ &csum_offset);
+ if (err < 0)
+ return err;
+
+ priv->csum_offset = csum_offset;
+ }
if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) {
u32 flags;

@@ -580,13 +586,14 @@ static int nft_payload_set_init(const struct nft_ctx *ctx,
priv->csum_flags = flags;
}

- switch (priv->csum_type) {
+ switch (csum_type) {
case NFT_PAYLOAD_CSUM_NONE:
case NFT_PAYLOAD_CSUM_INET:
break;
default:
return -EOPNOTSUPP;
}
+ priv->csum_type = csum_type;

return nft_validate_register_load(priv->sreg, priv->len);
}
--
2.35.1