[PATCH 5.4 030/165] netfilter: nf_tables: validate NFT_DATA_VALUE after nft_data_init()

Greg Kroah-Hartman
2020-01-11T10:23:22Z

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

[ Upstream commit 0d2c96af797ba149e559c5875c0151384ab6dd14 ]

Userspace might bogusly sent NFT_DATA_VERDICT in several netlink
attributes that assume NFT_DATA_VALUE. Moreover, make sure that error
path invokes nft_data_release() to decrement the reference count on the
chain object.

Fixes: 96518518cc41 ("netfilter: add nftables")
Fixes: 0f3cd9b36977 ("netfilter: nf_tables: add range expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 4 +++-
net/netfilter/nft_bitwise.c | 4 ++--
net/netfilter/nft_cmp.c | 6 ++++++
net/netfilter/nft_range.c | 10 ++++++++++
4 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 7120eba71ac5..4c03c14e46bc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4252,8 +4252,10 @@ static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
return err;

err = -EINVAL;
- if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
+ if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) {
+ nft_data_release(&elem.key.val, desc.type);
return err;
+ }

priv = set->ops->get(ctx->net, set, &elem, flags);
if (IS_ERR(priv))
diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
index 02afa752dd2e..10e9d50e4e19 100644
--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -80,7 +80,7 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
- if (d1.len != priv->len) {
+ if (d1.type != NFT_DATA_VALUE || d1.len != priv->len) {
err = -EINVAL;
goto err1;
}
@@ -89,7 +89,7 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
tb[NFTA_BITWISE_XOR]);
if (err < 0)
goto err1;
- if (d2.len != priv->len) {
+ if (d2.type != NFT_DATA_VALUE || d2.len != priv->len) {
err = -EINVAL;
goto err2;
}
diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index 0744b2bb46da..ae730dba60c8 100644
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -80,6 +80,12 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
if (err < 0)
return err;

+ if (desc.type != NFT_DATA_VALUE) {
+ err = -EINVAL;
+ nft_data_release(&priv->data, desc.type);
+ return err;
+ }
+
priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
err = nft_validate_register_load(priv->sreg, desc.len);
if (err < 0)
diff --git a/net/netfilter/nft_range.c b/net/netfilter/nft_range.c
index 4701fa8a45e7..89efcc5a533d 100644
--- a/net/netfilter/nft_range.c
+++ b/net/netfilter/nft_range.c
@@ -66,11 +66,21 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
if (err < 0)
return err;

+ if (desc_from.type != NFT_DATA_VALUE) {
+ err = -EINVAL;
+ goto err1;
+ }
+
err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
&desc_to, tb[NFTA_RANGE_TO_DATA]);
if (err < 0)
goto err1;

+ if (desc_to.type != NFT_DATA_VALUE) {
+ err = -EINVAL;
+ goto err2;
+ }
+
if (desc_from.len != desc_to.len) {
err = -EINVAL;
goto err2;
--
2.20.1