[PATCH nf,v2 1/2] netfilter: nft_payload: report ERANGE for too long offset and length

[PATCH nf,v2 1/2] netfilter: nft_payload: report ERANGE for too long offset and length

[Pablo Neira Ayuso]

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>
---
v2: no changes

 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 2e7ac007cb30..4fee67abfe2c 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -833,6 +833,7 @@ 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 ||
@@ -859,8 +860,13 @@ 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 && base != NFT_PAYLOAD_INNER_HEADER)
-- 
2.30.2

[PATCH nf,v2 2/2] netfilter: nft_payload: do not truncate csum_offset and csum_type

[Pablo Neira Ayuso]

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>
---
v2: missing priv->csum_offset.

 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 4fee67abfe2c..f2e131e45645 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -740,17 +740,23 @@ 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;
+	int err;
 
 	priv->base        = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
 	priv->offset      = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
 	priv->len         = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
 
 	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;
 
@@ -761,7 +767,7 @@ 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;
@@ -775,6 +781,7 @@ static int nft_payload_set_init(const struct nft_ctx *ctx,
 	default:
 		return -EOPNOTSUPP;
 	}
+	priv->csum_type = csum_type;
 
 	return nft_parse_register_load(tb[NFTA_PAYLOAD_SREG], &priv->sreg,
 				       priv->len);
-- 
2.30.2